WO2006088531A2 - Aneurysm treatment devices and methods - Google Patents

Aneurysm treatment devices and methods Download PDF

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Publication number
WO2006088531A2
WO2006088531A2 PCT/US2005/043362 US2005043362W WO2006088531A2 WO 2006088531 A2 WO2006088531 A2 WO 2006088531A2 US 2005043362 W US2005043362 W US 2005043362W WO 2006088531 A2 WO2006088531 A2 WO 2006088531A2
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WO
WIPO (PCT)
Prior art keywords
aneurysm
elastomeric matrix
implant
polycarbonate
lumen
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PCT/US2005/043362
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French (fr)
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WO2006088531A3 (en
Inventor
Ivan Sepetka
Maria Aboytes
Maybelle Jordan
Craig D. Friedman
Arindam Datta
Original Assignee
Biomerix Corporation
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Publication date
Priority claimed from US10/998,357 external-priority patent/US20060116709A1/en
Priority claimed from US11/111,487 external-priority patent/US8771294B2/en
Application filed by Biomerix Corporation filed Critical Biomerix Corporation
Publication of WO2006088531A2 publication Critical patent/WO2006088531A2/en
Publication of WO2006088531A3 publication Critical patent/WO2006088531A3/en

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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B17/12099Occluding by internal devices, e.g. balloons or releasable wires characterised by the location of the occluder
    • A61B17/12109Occluding by internal devices, e.g. balloons or releasable wires characterised by the location of the occluder in a blood vessel
    • A61B17/12113Occluding by internal devices, e.g. balloons or releasable wires characterised by the location of the occluder in a blood vessel within an aneurysm
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B17/12131Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
    • A61B17/1214Coils or wires
    • A61B17/12145Coils or wires having a pre-set deployed three-dimensional shape
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B17/12131Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
    • A61B17/1214Coils or wires
    • A61B17/1215Coils or wires comprising additional materials, e.g. thrombogenic, having filaments, having fibers, being coated
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B17/12131Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
    • A61B17/12163Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device having a string of elements connected to each other
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B17/12131Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
    • A61B17/12168Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device having a mesh structure
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B17/12131Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
    • A61B17/12168Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device having a mesh structure
    • A61B17/12172Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device having a mesh structure having a pre-set deployed three-dimensional shape
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B17/12131Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
    • A61B17/12181Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device formed by fluidized, gelatinous or cellular remodelable materials, e.g. embolic liquids, foams or extracellular matrices
    • A61B17/1219Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device formed by fluidized, gelatinous or cellular remodelable materials, e.g. embolic liquids, foams or extracellular matrices expandable in contact with liquids
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B2017/00477Coupling
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B2017/00831Material properties
    • A61B2017/00862Material properties elastic or resilient
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B2017/1205Introduction devices
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B2017/1205Introduction devices
    • A61B2017/12054Details concerning the detachment of the occluding device from the introduction device
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/12Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
    • A61B17/12022Occluding by internal devices, e.g. balloons or releasable wires
    • A61B2017/1205Introduction devices
    • A61B2017/12054Details concerning the detachment of the occluding device from the introduction device
    • A61B2017/12095Threaded connection
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B90/00Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
    • A61B90/39Markers, e.g. radio-opaque or breast lesions markers

Definitions

  • This invention relates to methods and devices for the treatment of vascular aneurysms and other comparable vascular abnormalities. More particularly, this invention relates to occlusion devices for vascular aneurysms that comprise a reticulated elastomeric matrix structure and a delivery device.
  • the cardio-vascular system when functioning properly, supplies nutrients to all parts of the body and carries waste products away from these parts for elimination. It is essentially a closed-system comprising the heart, a pump that supplies pressure to move blood through the blood vessels, blood vessels that lead away from the heart, called arteries, and blood vessels that return blood toward the heart, called veins.
  • arteries blood vessels that lead away from the heart
  • veins blood vessels that return blood toward the heart
  • aorta On the discharge side of the heart is a large blood vessel called the aorta from which branch many arteries leading to all parts of the body, including the organs.
  • the arteries dimmish to small arteries, still smaller arteries called arterioles, and ultimately connect to capillaries.
  • Capillaries are minute vessels where outward diffusion of nutrients, including oxygen, and inward diffusion of wastes, including carbon dioxide, takes place. Capillaries connect to tiny veins called venules.
  • Venules in turn connect to larger veins which return the blood to the heart by way of a pair of large blood vessels called the inferior and superior venae cava.
  • arteries 2 and veins comprise three layers known as tunics.
  • An inner layer 4 called the tunica interna, is thin and smooth, constituted of endothelium, and rests on a connective tissue membrane rich in elastic and collagenous fibers that secrete biochemicals to perform functions such as prevention of blood clotting by inhibiting platelet aggregation and regulation of vasoconstriction and vasodilation.
  • a middle layer 6 called the tunica media is made of smooth muscle 8 and elastic connective tissue 10 and provides most of the girth of the blood vessel.
  • the tunica media 6 differentiates an artery from a vein in that it is thicker in an artery to withstand the higher blood pressure exerted by the heart on the walls of the arteries. Tough elastic connective tissue provides an artery 2 sufficient elasticity to withstand the blood pressure and sudden increases in blood volume that occur with ventricular contractions.
  • the blood pressure can dilate or expand the region of the artery 2 with the weakness, and a pulsating sac 14 called a berry or saccular aneurysm (Figure 2), can develop. If the walls of the arteries 2 expand around the circumference of the artery 2, this is called a fusiform aneurysm 16 ( Figure 3). If the weakness causes a longitudinal tear in the tunica media of the artery, it is called a dissecting aneurysm. Saccular aneurysms are common at artery bifurcations 18 ( Figures 4 and 5) located around the brain.
  • aneurysms Dissecting aneurysms are common in the thoracic and abdominal aortas.
  • the pressure of an aneurysm against surrounding tissues, especially the pulsations, may cause pain and may also cause tissue damage.
  • aneurysms are often asymptomatic.
  • the blood in the vicinity of the aneurysm can become turbulent, leading to formation of blood clots, that may be carried to various body organs where they may cause damage in varying degrees, including cerebrovascular incidents, myocardial infarctions and pulmonary embolisms. Should an aneurysm tear and begin to leak blood, the condition can become life threatening, sometimes being quickly fatal, in a matter of minutes.
  • aneurysms are non-existent. Therefore, the description of the present invention is related to arteries, but applications within a vein, if useful, are to be understood to be within the scope of this invention.
  • Greene's hydrogel lacks the mechanical properties to enable it to regain its size and shape in vivo were it to be compressed for catheter, endoscope, or syringe delivery, and the process can be complex and difficult to implement.
  • Other patents disclose introduction of a device, such as a stent or balloon (Naglreiter et al., U.S. Patent No. 6,379,329) into the aneurysm, followed by introduction of a hydrogel in the area of the stent to attempt to repair the defect (Sawhney et al., U.S. Patent No. 6,379,373).
  • Still other patents suggest the introduction into the aneurysm of a device, such as a stent, having a coating of a drug or other bioactive material (Gregory, U.S. Patent No. 6,372,228).
  • Other methods include attempting to repair an aneurysm by introducing via a catheter a self-hardening or self-curing material into the aneurysm. Once the material cures or polymerizes in situ into a foam plug, the vessel can be recanalized by placing a lumen through the plug (Hastings, U.S. Patent No. 5,725,568).
  • Another group of patents relates more specifically to saccular aneurysms and teaches the introduction of a device, such as string, wire or coiled material (Boock U.S. Patent No. 6,312,421), or a braided bag of fibers (Greenhalgh, U.S. Patent No. 6,346,117) into the lumen of the aneurysm to fill the void within the aneurysm.
  • the device introduced can carry hydrogel, drugs or other bioactive materials to stabilize or reinforce the aneurysm (Greene Jr. et al., U.S. Patent No. 6,299,619).
  • Another treatment known to the art comprises catheter delivery of platinum microcoils into the aneurysm cavity in conjunction with an embolizing composition comprising a biocompatible polymer and a biocompatible solvent.
  • the deposited coils or other non-particulate agents are said to act as a lattice about which a polymer precipitate grows thereby embolizing the blood vessel (Evans et al., U.S. Patent No. 6,335,384).
  • any implanted device must be present in the body for a long period of time, and must therefore be resistant to rejection, and not degrade into materials that cause adverse side effects.
  • platinum coils may be having some benefits in this respect, they are inherently expensive, and the pulsation of blood around the aneurysm may cause difficulties such as migration of the coils, incomplete sealing of the aneurysm, or fragmentation of blood clots.
  • the use of a coil is frequently associated with recanalization of the site, leading to full or partial reversal of the occlusion. If the implant does not fully occlude the aneurysm and effectively seal against the aneurysm wall, pulsating blood may seep around the implant and the distended blood vessel wall causing the aneurysm to reform around the implant.
  • vascular occlusion devices such as coils, thrombin, glue, hydrogels, etc.
  • have serious limitations or drawbacks including, but not limited to, early or late recanalization, incorrect placement or positioning, migration, and lack of tissue ingrowth and biological integration.
  • some of the devices are physiologically unacceptable and engender unacceptable foreign body reactions or rejection.
  • there is a need for more effective aneurysm treatment that produces permanent biological occlusion can be delivered in a compressed state through small diameter catheters to a target vascular or other site with minimal risk of migration, will prevent the aneurysm from leaking or reforming.
  • an aneurysm treatment device for in situ treatment of aneurysms, particularly, cerebral aneurysms, in mammals, especially humans.
  • the treatment device comprises a resiliently collapsible implant comprised of a reticulated, biodurable elastomeric matrix, which is collapsible from a first, expanded configuration wherein the implant can support the wall of an aneurysm to a second collapsed configuration wherein the collapsible implant is deliverable into the aneurysm, for example, by being loadable into a catheter and passed through the patient's vasculature.
  • useful aneurysm treatment devices can have sufficient resilience, or other mechanical property, including expansion, to return to an expanded configuration within the space of the aneurysm and to occlude the aneurysm.
  • the implant is configured so that hydraulic forces within the aneurysm coupled with recovery and resilience characteristics of the reticulated elastomeric matrix tend to urge the implant against the aneurysm wall.
  • an implant comprises one or more flexible, connected, preferably spherically-, ellipsoidally-, or cylindrically- shaped structures that are positioned in a compressed state in a delivery catheter.
  • the connected structures preferably have spring coils on each end, one of which coils is releasably secured within the delivery catheter.
  • a longitudinally extending rod or wire that acts to assist in pushing the implant distally extends through the structures and is withdrawn during delivery. The implant tends to form a spiral shape after delivery.
  • an implant that is initially essentially cylindrical in shape in connection with a delivery catheter comprises a mechanism such that when the structure is positioned at a desired location, the mechanism is engaged to cause the structure to assume any particular shape that will occlude an aneurysm.
  • an implant for occlusion of an aneurysm comprises reticulated elastomeric matrix in a shape that can be compressed, can be inserted into a delivery catheter, can be ejected or deployed from the delivery catheter into an aneurysm, and can then expand to sufficient size and shape to occlude the aneurysm.
  • Such shapes include, but are not limited to, spheres, hollow spheres, cylinders, hollow cylinders, noodles, cubes, pyramids, tetrahedrons, hollow cylinders with lateral slots, trapezoids, parallelepipeds, ellipsoids, rods, tubes, or elongated prismatic forms, folded, coiled, helical or other more compact configurations, segmented cylinders where "sausage-like" segments have been formed, flat square or rectangular shapes, daisy shapes, braided shapes, or flat spiral shapes, optionally with surgical suture or radiopaque wire support extending therein.
  • implantable device or devices for vascular malformation applications have a volume of at least about 50% of the aneurysm volume.
  • the ratio of implant (or implants) volume to aneurysm volume is defined as packing density.
  • such implantable device or devices for vascular malformation applications have a volume of at least about 75% of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 125 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 175% of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 200 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 300 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 400 % of the aneurysm volume.
  • the packing density is targeted to achieve angiographic occlusion after embolization of the aneurysm by the implant, followed by clotting, thrombosis, and tissue ingrowth, ultimately leading to biological obliteration of the aneurysm sac. Permanent tissue ingrowth will prevent any possible recanalization.
  • the implant be treated or formed of a material that will encourage such fibroblast immigration. It is also desirable that the implant be configured, with regard to its three-dimensional shape, and its size, resiliency and other physical characteristics, and be suitably chemically or biochemically constituted to foster eventual tissue ingrowth and formation of scar tissue that will help fill and/or obliterate the aneurysm sac.
  • the aneurysm treatment device preferably comprises a reticulated biodurable elastomeric matrix or the like that is capable of being compressed and inserted into a catheter for implantation.
  • the implant can be formed of a partially hydrophobic reticulated biodurable elastomeric matrix having its pore surfaces coated to be partially hydrophilic, for example, by being coated with at least a partially hydrophilic material, optionally a partially hydrophilic reticulated elastomeric matrix.
  • the entire foam has such a hydrophilic coating throughout the pores of the reticulated elastomeric matrix.
  • the hydrophilic material carries a pharmacologic agent, for example, elastin to foster fibroblast proliferation. It is also within the scope of the invention for the pharmacologic agent to include sclerotic agents, inflammatory induction agents, growth factors capable of fostering fibroblast proliferation, or genetically engineered an/or genetically acting therapeutics.
  • the pharmacologic agent or agents preferably are dispensed over time by the implant. Incorporation of biologically active agents in the hydrophilic phase of a composite foam suitable for use in the practice of the present invention is described in co-pending, commonly assigned U.S. patent applications Serial No. 10/692,055, filed October 22, 2003, Serial No. 10/749,742, filed December 30, 2003, Serial No. 10/848,624, filed May 17, 2004, and Serial No. 10/900,982, filed July 27, 2004, each of which is incorporated herein by reference in its entirety.
  • the invention provides a method of treating an aneurysm comprising the steps of:
  • the method further comprises:
  • aneurysm treatment device positioning and releasing the aneurysm treatment device in the aneurysm.
  • suitable imaging technology such as a magnetic resonance image (MRI), computerized tomography scan (CT Scan), x-ray imaging with contrast material or ultrasound, and is to be treated
  • the surgeon chooses which implant he or she feels would best suit the aneurysm, both in shape and size.
  • the implant can be used alone.
  • the aneurysm treatment device of the invention may also be used in conjunction with a frame of platinum coils to assist in reducing or eliminating the risk of implant migration out of the neck of the aneurysm. This is particularly true in the case of wide neck or giant aneurysms.
  • the implant is then loaded into an intravascular catheter in a compressed state.
  • the implant can be provided in a sterile package in a pre-compressed configuration, ready for loading into a catheter.
  • the implants can be made available in an expanded state, also, preferably, in a sterile package, and the surgeon at the site of implantation can use a suitable secondary device or a loader apparatus to compress an implant so that it can be loaded into a delivery catheter.
  • the catheter With an implant loaded into the catheter, the catheter is advanced through an artery to the diseased portion of the affected artery using any suitable technique known in the art. By use of the catheter the implant is then inserted and positioned within the aneurysm. As the implant is released from the catheter, where it is in its compressed state, it expands and is manipulated into a suitable position within the aneurysm.
  • Figure 1 is a side view of an artery with layers partially cut away to illustrate the anatomy of the artery;
  • Figure 2 is a longitudinal cross-section of an artery with a saccular aneurysm
  • Figure 3 is a longitudinal cross-section of an artery with a fusiform aneurysm
  • Figure 4 is a top view of an artery at a bifurcation
  • Figure 5 is a top view of an artery at a bifurcation with a saccular aneurysm at the point of bifurcation;
  • Figures 6 to 8 illustrate an embodiment of the invention wherein a segmented vascular occlusion device is deployed
  • Figures 9 and 10 illustrate a further embodiment of the invention where a vascular occlusion device is fixed in position
  • Figures 11 to 24B represent embodiments of implants and delivery systems useful according to the invention.
  • Figures 25 and 26 represent micrographs of tissue ingrowth
  • Figures 27A to 27C represent different stages of embolization formation in a dog. DETAILED DESCRIPTION OF THE INVENTION
  • the present invention relates to a system and method for treating aneurysms, particularly cerebral aneurysms, in situ.
  • an aneurysm treatment device comprising a reticulated, biodurable elastomeric matrix implant designed to be permanently inserted into an aneurysm with the assistance of an intravascular catheter.
  • Reticulated matrix, from which the implants are made has sufficient and required liquid permeability and thus selected to permit blood, or other appropriate bodily fluid, and cells and tissues to access interior surfaces of the implants. This happens due to the presence of interconnected and inter-communicating, reticulated open pores and/or voids and/or channels that form fluid passageways or fluid permeability providing fluid access all through.
  • inventive aneurysm treatment device or implant is designed to cause angiographic occlusion, followed by clotting, thrombosis, and eventually bio-integration through tissue ingrowth and proliferation.
  • inventive aneurysm treatment device can carry one or more of a wide range of beneficial drugs and chemical moieties that can be released at the affected site for various treatments, such as to aid in healing, foster scarring of the aneurysm, prevent further damage, or reduce risk of treatment failure. With release of these drugs and chemicals locally, employing the devices and methods of the invention, their systemic side effects are reduced.
  • An implant or occlusion device can comprise a reticulated biodurable elastomeric matrix or other suitable material and can be designed to be inserted into an aneurysm through a catheter.
  • a preferred reticulated elastomeric matrix is a compressible, lightweight material, designed for its ability to expand within the aneurysm without expanding too much and tearing the aneurysm.
  • implantable device or devices for vascular malformation applications have a volume of at least about 50% of the aneurysm volume.
  • the ratio of implant (or implants) volume to aneurysm volume is defined as packing density.
  • implantable device or devices for vascular malformation applications have a volume of at least about 75% of the aneurysm volume.
  • implantable device or devices for vascular malformation applications have a volume of at least about 125 % of the aneurysm volume.
  • such implantable device or devices for vascular malformation applications have a volume of at least about 175% of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 200 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 300 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 400 % of the aneurysm volume. Insertion of the implant followed by tissue ingrowth should result in total obliteration of the aneurysm sac.
  • the implant can also contain one or more radiopaque markers for visualization by radiography or ultrasound to determine the orientation and location of the implant within the aneurysm sac.
  • plantinum markers are incorporated in the implant and/or relevant positions of delivery members.
  • the outer surfaces of the implant or occlusion device can be coated, after fabrication of the implant or occlusion device with functional agents, such as those described herein, optionally employing an adjuvant that secures the functional agents to the surfaces and to reticulated elastomeric matrix pores adjacent the outer surfaces, where the agents will become quickly available.
  • Such external coatings which may be distinguished from internal coatings provided within and preferably throughout the pores of reticulated elastomeric matrix used, may comprise fibrin and/or other agents to promote fibroblast growth.
  • an aneurysm has been identified using suitable imaging technology, such as a magnetic resonance image (MRI), computerized tomography scan (CT Scan), x-ray imaging with contrast material or ultrasound, the surgeon chooses which implant he or she feels would best suit the aneurysm, both in shape and size.
  • the chosen implant is then loaded into an intravascular catheter in a compressed state.
  • the implants can be sold in a sterile package containing a pre-compressed implant that is loaded into a delivery catheter.
  • the implant can be sold in a sterile package in an expanded state, and the surgeon at the site of implantation can use a device, e.g. a ring, funnel or chute that compresses the implant for loading into the catheter.
  • the catheter is then advanced through an artery to the diseased portion of the affected artery using any of the techniques common in the art. Using the catheter the implant is then inserted and positioned within the aneurysm. Once the implant is released from its compressed state, it is allowed to expand within the aneurysm.
  • implants or occlusion devices are intended to cause angiographic occlusion of the aneurysm sac.
  • the implants of the invention can, if desired, comprise reticulated biodurable elastomeric implants having a materials chemistry and microstructure as described herein.
  • a foam structure 50 comprises two or more sections 52, preferably from about 2 to about 100, that are defined by radiopaque rings, e.g., platinum rings or compression members 54 or similar mechanisms.
  • Foam sections 52 comprise a longitudinally extending flexible mesh 58 defining a lumen 62.
  • a distal spring section 64 attached to the distal end 66 of structure 50 comprises a distal tip 68 and a lumen 70 in communication with lumen 62.
  • a proximal spring 72 is attached to proximal end 74 and has a lumen 76 extending therethrough.
  • a flexible but rigid wire 78 extends through lumen 76, lumen 62, and lumen 70.
  • Wire 78 has a radiopague tip marker 60.
  • Flexible mesh 58 extends distally as a jacket to cover coil 64 and proximally as a jacket to cover coil 72.
  • Compressed structure 50 is positioned within a delivery catheter 80 that has a longitudinally extending lumen 82 and a distal radiopaque marker 86.
  • the proximal end 88 of catheter 80 has a narrowed opening 90 that slidably engages a pushing catheter 94.
  • the proximal end 96 of pushing catheter 94 slidably engages the proximal section 98 of wire 78.
  • the distal end 102 of pushing catheter 94 comprises a radiopaque marker 104 and an opening 106.
  • a flexible loop or wire 108 attached to coil 76 extends through opening 106 to engage wire 78.
  • pusher catheter 94 and wire 78 are advanced distally. As portions of structure 50 extend distally past the distal end 110 of delivery catheter 80, wire 78 is withdrawn in the proximal direction. Eventually, as shown in Figure 8, wire 78 is withdrawn past opening 106 so that flexible wire 108 releases and structure 50 is free from delivery catheter 80.
  • coils 70 and 76 and mesh 58 comprise a biocompatible shape memory alloy or polymer such as nitinol, so that the released structure will assume a non-linear, preferably helical or irregular, shape.
  • FIG. 7 the implant is still connected to the delivery "system" via connecting number 108. This is important because the implant can in this partially delivered condition be maneuvered within the patient to either reposition the implant to optimize placement allowing for a controlled delivery, or even to withdraw or retrieve the implant altogether.
  • FIG. 9 Another embodiment of the invention, a shown in Figures 9 and 10, comprises a delivery catheter 130 and a vascular occlusion device 132 positioned at the distal end 134 of catheter 130. Extending within a lumen 136 of catheter 130 and through a lumen formed by a coil 138 in occlusion device 132 is a delivery member 140 that has a distal section 142, a middle section 144, and a proximal section 146. A guidewire 150 extends through lumen 152 formed within delivery member 140.
  • Coil 138 is wound from one single nitinol wire but it has sections with two different diameters.
  • Coil proximal end 154 and coil distal end 156 which are like two "nuts", each have the same diameter, corresponding to and able to engage the diameter of delivery member middle section 144.
  • the center part of coil 138 has larger a diameter, so that delivery member 140 can move through it freely.
  • occlusion device 132 To attach occlusion device 132 in a delivery position, it needs to be stretched from a spherical or ball shape into a low profile cylindrical shape by use of a stretching device (not shown). Once device 132 is stretched, it can be locked by inserting delivery member 140 with distal section 142 and engaging proximal nut 154 and distal nut 156 by screw segment 144 to remain in a stretched position for delivery.
  • occlusion device 132 can be released by rotating section 144 proximally catheter 130. As soon as section 144 unscrews from distal nut 156 into the center part of coil 138, the memory force of coil 138 will start compressing back to a sphical or ball shape, as shown in Figure 10, while section 144 moves proximally from proximal nut 154. Detachment will occur after section 144 unscrews completely from proximal nut 154 of coil 138 and soft distal tip 142 is pulled back into catheter 130. Occlusion device 132 is then released from delivery member 140 at a desired location.
  • Occlusion device 132 comprises shape memory metallic or polymeric members 158, preferably nitinol, to which a foam layer 160 is attached.
  • an implant 182 is formed from a foam member 184 optionally having a round, square, ellipsoidal, or rectangular cross-section. Radiopaque, preferably platinum, markers 186 are positioned or crimped every about 2 to about 10 mm to form a chain or noodle-like structure. Implant 182 has a reinforcing filament 190 extending through the entire length of implant 182 to prevent implant 182 from breaking or fragmenting, to provide support for pulling and/or pushing during delivery or deployment, and to prevent migration during delivery or deployment.
  • Reinforcing filament 190 can be biosorbable or non-resorbable, preferably non-resorbable, and can be comprised of a polymer such as polyester, a radiopaque metal such as platinum, or a combination thereof, including, but not limited to, known suture materials or suture composites. Moreover, reinforcing filament 190 can be a monofilament, braided rope or wire, or a wire or cable.
  • the length of implant 182 could be from about 5 mm to about 800 mm, preferably from about 50 mm to about 600 mm, and the diameter or effective diameter could be from about 0.25 mm to about 10 mm, preferably from about 0.50 mm to about 2 mm.
  • the implant 192 in Figure 12 comprises two or more, preferably from about 3 to 6, cylindrical or string segments 194 that are held together by a reinforcing filament (not shown) or marker 196 for structural integrity for delivery or deployment or to be blended with other components.
  • a reinforcing filament not shown
  • marker 196 are crimped from about 2 to about 10 mm apart.
  • the length and effective diameter of implant 192 are approximately the same as those of implant 182.
  • Implant 200 also known as "foam on a string” or a NEUROSTRINGTM implant," is shown in Figures 6 and 7.
  • Implant 200 is formed from an elastomeric matrix member 202 having a round, square, ellipsoidal, multi-sided, polygonal, or rectangular, but preferably round, cross-section.
  • implant 200 is formed from an elastomeric matrix member 202 having an irregular shape.
  • the cross-section of elastomeric matrix 202 can be of regular cross-section for part of the length of implant 200 and can be of irregular cross-section for part of the length of implant 200, that is, a combination of regular cross-section and irregular cross-section.
  • the topology of biodurable reticulated elastomeric matrix 202 can be of regular cross-section for part of the length of implant 200 and can be of irregular cross-section for part of the length of implant 200, that is, a combination of regular cross-section and irregular cross-section.
  • matrix member 202 is biodurable and reticulated.
  • Two longitudinally extending, essentially parallel structural filaments 204 and 206 extend the length of implant 200, and at regular intervals structural filaments 204 and 206 form knots or ropes 208 that define matrix subsections 210.
  • a purpose of the knots is to secure the structural filament to the elastomeric matrix. This can be seen more clearly in the detail of Figure 7.
  • Structural filaments 204 and 206 can be biosorbable or non-resorbable, preferably non-resorbable, and comprised of a polymer such as polyester, a radiopaque metal such as platinum, or a combination thereof, including, but not limited to, known polymeric fiber or filament materials or polymeric fiber or filament composites.
  • reinforcing filaments 204 and 206 can each be a monofilament, braided rope or wire, or a wire or cable.
  • the length of implant 200 could be from about 5 mm to about 1500 mm, preferably from about 1 cm to about 50 cm, and the diameter or effective diameter could be from about 0.25 mm to about 12 mm, preferably from about 0.50 mm to about 0.5 mm.
  • the foam sections are each from about 0.5 mm to about 1 cm in length. Each foam section 210 is carefully trimmed or shaved by hand to a desired diameter. The outer diameter of each foam section should be equal to or slightly less than the inner diameter of the corresponding introducer sheath, discussed below.
  • the reinforcing filaments 204 and 206 can be inserted into implant 200 by hand or by mechanical means such as a mechanical stitching or sewing machine.
  • one or more elongate structural members in the device such as filaments, may be included and, if so, may be provided with features or coupled to one another to confer desired properties.
  • Filament 204 may be polymeric fiber, carbon fiber, glass fiber, synthetic suture, a single platinum wire, other metallic fiber, a twist or braid of platinum wire and polymeric fiber or filament, or twisted or braided double platinum wires or other materials or combinations thereof.
  • Filament 206 is polymeric fiber or other filament such as are described above.
  • Filament 204 or filament 206 can also be a monofilament fiber, co- mingled fibers, knotted, twisted braided rope, wire, a cable, composite scaffold, mesh, woven mesh or knitted mesh, or other material, structure or combination.
  • filament 204 can be a structural element.
  • Filament 204 may comprise a subassembly prepared using a coil winder and separate spools of fibers used to make polymeric fibers or filaments and platinum wires of differing thicknesses, thereby creating a twisted rope-like composite subassembly with varying stiffness and radiopacity.
  • Known methods such as braiding may also be used to create such a subassembly.
  • filament 204 may be available on separate spools or spindles and the final structural element can be formed during the attachment or the incorporation of the matrix member 202 to filament 204.
  • filament 204 may comprise a sub- assembly in which a platinum micro coil string wound from platinum micro wire, over a fiber core or over the platinum wire core, will provide more integrity for pull/push action including good radiopacity. Construction or fabrication of filament 204 can be achieved in, for example, by using a sewing machine. Instead of using twisted platinum wire with fiber into braid and than loaded into sawing machine, in one embodiment a regular coil having inner core fiber or platinum wire is then loaded into the sewing machine to get knotted with the second sewing machine polymeric fiber or filament or wire string.
  • the platinum wire useful according to the invention preferably has a diameter of from about 0.0005 in. to about 0.005 in., more preferably from about 0.001 in. to about 0.003 in. Suitable platinum wire is available from sources such as Sigmund Cohn Corp.
  • the fibers useful according to the invention comprise commercially available, non-absorbable polymeric fibers used to make suture fiber or filament having an effective diameter of from about 0.0005 in. to about 0.010 in., preferably from about 0.010 in. to about 0.005 in.
  • the fibers are available on spools and have compositions and diameters comparable to commercially available sutures, for example, sutures available from Johnson & Johnson under the name ETHIBOND EXCEL®, PROLENE®, ETHILON®, Coated VICRYL®, or MONOCRYL®.
  • Varying the structural filaments results in implants according to the invention having different characteristics.
  • the resulting implant is "Ultra Soft", as set forth in the table below.
  • the resulting implant is "Soft” or "Stiff.
  • the stiffness of the device can be measured by the slope of the load versus extension curves during an uniaxial tensile pull using a tensile testing machine and can be in the range of from 1 to 200 pounds per inch (0.18 N/mm to 35 N/mm), preferably in the range of from 5 to 100 pounds per inch (0.88 N/mm to 18 N/mm).
  • the breaking strength of the device can be measured during an uniaxial tensile pull using a tensile testing machine and can be in the range of from approximately 0.05 to 23 pounds (0.2 to 100 Newtons) and preferably in the range of approximately 0.05 to 7 pounds (1.0 to 30 Newtons).
  • Ultra Soft implant requires use of a delivery system with a longitudinally extending core-wire to support the implant, an example of which delivery system can be seen in co-pending, commonly assigned U.S. patent application Serial No. 11/229,044, filed September 15, 2005, incorporated herein by reference, especially Figure 16 and the supporting language therefore, or hydraulic injection with a syringe. Delivery of the Soft or Stiff implants requires a pusher member as described below in Figures 15, 16, and 17.
  • one structural filament is a platinum wire and the other structural filament is polymeric fiber or filament
  • the resulting implant behaves like a coil to form helical packing during deployment into the aneurysm sac.
  • a significant difference between an implant of the invention and a coil is that the implant of the invention does not have a predetermined memory, as does a coil.
  • the implant of the invention is malleable and will conform to the dimensions of the aneurysm sac.
  • the stiffness can be controlled by varying the diameter of the platinum wire or the structure, as shown above, and the filament structure can act as a framing structure in lieu of the framing coils or stent necessary with a softer implant.
  • the stiffness can also be controlled by varying the number of platinum wires used.
  • the stiffer implants function to prevent migration and to facilitate better packing of the aneurysm sac, while the softer versions can be used as filler material to optimally embolize the aneurysm.
  • This stiffer implant may be more useful for different vessel occlusion applications within the body. Delivery of the stiffer implant can be accomplished with a regular delivery system not having a supporting core-wire mandrel or hydraulic injection.
  • each filament can be a platinum wire.
  • the resulting implant will be similar to the implant described above but slightly stiffer and more radiopaque.
  • implant 200 has regularly spaced radiopaque markers that are attached to every second to every sixth knot, preferably every third or fourth knot. These radiopaque markers tend to encourage the chain-like behavior that is characteristic of this embodiment. Notching of the elastomeric matrix/structural assembly and optional periodic crimping of platinum marker bands will allow the implant of the invention to bend and fold when deployed in an aneurysm and break like a chain. This bending and folding allows the implant to conformally fill the aneurysm sac like a liquid when deployed from the microcatheter.
  • the overall resultant phenomenon is again similar to that of spaghetti filling a bowl or a metallic chain folding onto itself.
  • the implant fills the aneurysm sac in a manner similar to that of very viscous liquid flow.
  • the implants or devices form shapes containing curvatures or those that fold onto themselves optionally can be compressed further as they make contact during delivery with themselves or with other delivered devices in the aneurysm or with wall of the aneurysm, thereby making it easier to pack in a superior fashion.
  • Platinum marker bands will impart additional radiopacity.
  • radiopaque microstaples instead of the radiopaque markers could be regularly spaced along the length of the implant every second to every sixth knot. This configuration would also encourage chain-like behavior.
  • a packaging system 218 for the storage and/or introduction of an implant such as implant 200 or other implants according to the invention is shown in Figure 15.
  • Proximal end 214 of implant 200 is engaged within an introducer sheath 220 by the distal end 222 of a pusher rod or member 224.
  • the proximal end 226 of sheath 220 engages the distal portion 228 of a manifold or side arm 230, which has an opening 232 for continuous flush.
  • Pusher member 224 extends proximally through valve 234, and pusher member 224 has a lumen (not shown) which receives an interlocking wire 238, which provides support to pusher member 224 and helps retain implant 200.
  • a flushing solution such as saline solution is introduced into opening 232 of system 218 to remove air and straighten out implant 200.
  • the tapered distal tip 242 of sheath 220 is introduced with continuous flushing into the hemostastis valve 244 of a side arm 246 of a micro-catheter as'sembly 248 such as is shown in Figure 16.
  • Sheath 220 is inserted into micro-catheter 250, after which sheath 220 and side arm 230 are withdrawn, leaving implant 200, pusher member 224, and interlocking wire 238.
  • Implant 200 Delivery of implant 200 is shown in Figures 16 and 17, where the distal end 216 of implant 200 is advanced through micro-catheter 250 and through an artery 252 to a position adjacent an aneurysm 254. Implant 200 is advanced further to fill aneurysm 254. When aneurysm 254 has been filled, as shown in Figure 17, the distal end 222 of pusher rod 224 is disengaged from implant 200 and withdrawn through micro-catheter 250.
  • Distal end member 262 comprises a lateral opening 264 to receive loop 212 from implant 200 and threading 266.
  • the distal end 268 of wire 238 has reciprocal threads 270 that engage threading 266. In the position shown in Figure 18, the distal end 268 of wire 238 is adjacent to the internal end surface 274 of distal end 262, to trap loop 212.
  • wire 238 is rotated to cause wire 238 to disengage from threading 266, loop 212 disengages from wire 238 and pusher member 224 and releases implant 200.
  • distal end member 262 comprises radiopaque material such as platinum to assist an operator during delivery.
  • distal end member 262 could comprise a section of platinum hypotube.
  • the distal end 268 of wire 238 is also radiopaque, which assists the operator during the procedure.
  • Advancing through the micro-catheter 250 provides controlled delivery or retraction of implant 200 into the aneurysm cavity with the pusher member 224 until desired positioning of implant 200 is accomplished. Due to the nature of the implant material, the implant fills the aneurysm cavity like a liquid complying with the geometry of the cavity. Continuous flush or pump of hydraulically pressurized solution such as saline solution is applied via micro-catheter through the micro- catheter side arm at the proximal end to support or drive the advancement of the implant through the catheter lumen.
  • the packing density that is, the ratio of volume of embolic material to volume of the aneurysm sac, ranges from about 50 to about 200%.
  • Implant 200 can be retracted, before it is detached, and repositioned for precise, controlled deployment and delivery.
  • Implant 200 is not self-supporting and has no predetermined shape. It conforms significantly better to the geometry of the aneurysm than other implants due to the formation of a light, non-traumatic "string-ball" casting the cavity like a liquid. Because of this important feature the implant material will provide permanent stability of the desired total occlusion.
  • An additional important feature of implant 200 is that it provides excellent tissue ingrowth to seal the aneurysm cavity from the parental artery. There is superior tissue ingrowth due to the porous nature of the reticulated matrix enhanced by structural reticulation created by plication/folding within the aneurysm. Also, plication enhances conformal space filling that eliminates device compaction and recanalization.
  • the implant 298 shown in Figures 2OA and 2OB comprises a flat, preferably square or rectangular, member 300 that can be rolled up to fit in a delivery catheter (not shown).
  • Member 300 preferably has surgical sutures, optionally absorbable, or radiopaque wire 302 sewn around the outer edges 304 and also diagonally 306.
  • implant 298 can be rolled up to fit within a lumen of a delivery catheter. Upon deployment implant 298 would unroll to fill an aneurysm sac.
  • An advantage of this particular embodiment is the relatively large surface area that is available for occlusion. It is anticipated that implant 298 could be from about 0.25 mm to about 3 mm in thickness and from about 1 mm to about 50 mm in length on the lateral edges.
  • Figure 21 represents an implant 310 where a thin string structure 312 has been cut from a flat member 314. Structure 312 is similar to implant 182 but with or without the internal suture or wire member. Manufacturing implant 310 in this manner provided memory support without nitinol support.
  • Figures 22A and 22B represent structures that may have an unexpanded shape, for example, cylindrical shape 318, that expands to an expanded shape, for example, spherical shape 320, due to internal frames (not shown).
  • the outer surface 322 of shape 320 could comprise coils or braids, for example, or different shapes can be sutured together using coils and/or patches to provide maximum surface area for occlusion.
  • Implant 324 shown in Figures 23 A and 23B is representative of a nitinol or other shape-memory wire member 326 having a foam cover 328. Implant 324 is compressed for delivery, as shown in Figure 23 A, and then expands to the configuration shown in Figure 23B upon deployment. [0090] A cylindrically-shaped implant 330 with slots 332 is shown in Figures
  • implant 330 may have one or more radiopaque bend markers 334.
  • An advantage of this shape is that the slots permit the implant to bend to maximize surface area during deployment.
  • Examples of such shapes include, but are not limited to, spheres, hollow spheres, cylinders, hollow cylinders, noodles, cubes, pyramids, tetrahedrons, hollow cylinders with lateral slots, trapezoids, parallelepipeds, ellipsoids, rods, tubes, or elongated prismatic forms, folded, coiled, helical or other more compact configurations, segmented cylinders where "sausage-like" segments have been formed, flat square or rectangular shapes, daisy shapes, braided shapes, or flat spiral shapes, optionally with surgical suture or radiopaque wire support extending therein.
  • Certain embodiments of the invention comprise porous, reticulated biodurable elastomeric implants, which are also compressible and exhibit resilience in their recovery, that have a diversity of applications and can be employed, by way of example, in management of vascular malformations, such as for aneurysm control, arteriovenous malfunction, arterial embolization or other vascular abnormalities, or as substrates for pharmaceutically-active agent, e.g., for drug delivery.
  • vascular malformation includes but is not limited to aneurysms, arteriovenous malfunctions, arterial embolizations and other vascular abnormalities.
  • inventions include reticulated, biodurable elastomeric implants for in vivo delivery via catheter, endoscope, arthroscope, laparoscope, cystoscope, syringe or other suitable delivery-device and can be satisfactorily implanted or otherwise exposed to living tissue and fluids for extended periods of time, for example, at least 29 days.
  • atraumatic implantable devices that can be delivered to an in vivo patient site, for example a site in a human patient, that can occupy that site for extended periods of time without being harmful to the host.
  • implantable devices can also eventually become biologically integrated, e.g., ingrown with tissue.
  • an implantable system which, e.g., can optionally cause immediate thrombotic response leading to clot formation, and eventually lead to fibrosis, i.e., allow for and stimulate natural cellular ingrowth and proliferation into vascular malformations and the void space of implantable devices located in vascular malformations, to stabilize and possibly seal off such vascular abnormalities in a biologically sound, effective and lasting manner.
  • cellular entities such as fibroblasts and tissues can invade and grow into a reticulated elastomeric matrix.
  • ingrowth can extend into the interior pores and interstices of the inserted reticulated elastomeric matrix.
  • the elastomeric matrix can become substantially filled with proliferating cellular ingrowth that provides a mass that can occupy the site or the void spaces in it.
  • tissue ingrowth possible include, but are not limited to, fibrous tissues and endothelial tissues.
  • the implantable device or device system causes cellular ingrowth and proliferation throughout the site, throughout the site boundary, or through some of the exposed surfaces, thereby sealing the site. Over time, this induced fibrovascular entity resulting from tissue ingrowth can cause the implantable device to be incorporated into the aneurysm wall. Tissue ingrowth can lead to very effective resistance to migration of the implantable device over time. It may also prevent recanalization of the aneurysm.
  • the tissue ingrowth is scar tissue which can be long-lasting, innocuous and/or mechanically stable.
  • implanted reticulated elastomeric matrix becomes completely filled and/or encapsulated by tissue, fibrous tissue, scar tissue or the like.
  • AVM arteriovenous malformations
  • arteriovenous fistulas anomalies of feeding and draining veins
  • arteriovenous fistulas e.g., anomalies of large arteriovenous connections
  • abdominal aortic aneurysm endograft endoleaks e.g., inferior mesenteric arteries and lumbar arteries associated with the development of Type II endoleaks in endograft patients.
  • Shaping and sizing can include custom shaping and sizing to match an implantable device to a specific treatment site in a specific patient, as determined by imaging or other techniques known to those in the art.
  • one or at least two comprise an implantable device system for treating an undesired cavity, for example, a vascular malformation.
  • Implants useful in this invention or a suitable hydrophobic scaffold comprise a reticulated polymeric matrix formed of a biodurable polymer that is elastomeric and resiliently-compressible so as to regain its shape after being subjected to severe compression during delivery to a biological site such as vascular malformations described here.
  • the structure, morphology and properties of the elastomeric matrices of this invention can be engineered or tailored over a wide range of performance by varying the starting materials and/or the processing conditions for different functional or therapeutic uses.
  • the inventive implantable device is reticulated, i.e., comprises an interconnected network of pores and channels and voids that provides fluid permeability throughout the implantable device and permits cellular and tissue ingrowth and proliferation into the interior of the implantable device.
  • the inventive implantable device is reticulated, i.e., comprises an interconnected and/or intercommunicating network of pores and channels and voids that provides fluid permeability throughout the implantable device and permits cellular and tissue ingrowth and proliferation into the interior of the implantable device.
  • the inventive implantable device is reticulated, i.e., comprises an interconnected and/or intercommunicating network of pores and/or voids and/or channels that provides fluid permeability throughout the implantable device and permits cellular and tissue ingrowth and proliferation into the interior of the implantable device.
  • the biodurable elastomeric matrix or material is considered to be reticulated because its microstructure or the interior structure comprises inter-connected and intercommunicating pores and/or voids bounded by configuration of the struts and intersections that constitute the solid structure.
  • the continuous interconnected void phase is the principle feature of a reticulated structure.
  • Preferred scaffold materials for the implants have a reticulated structure with sufficient and required liquid permeability and thus selected to permit blood, or other appropriate bodily fluid, and cells and tissues to access interior surfaces of the implants. This happens due to the presence of inter-connected and intercommunicating, reticulated open pores and/or voids and/or channels that form fluid passageways or fluid permeability providing fluid access all through.
  • Preferred materials are at least partially hydrophobic reticulated, elastomeric polymeric matrix for fabricating implants according to the invention are flexible and resilient in recovery, so that the implants are also compressible materials enabling the implants to be compressed and, once the compressive force is released, to then recover to, or toward, substantially their original size and shape.
  • an implant can be compressed from a relaxed configuration or a size and shape to a compressed size and shape under ambient conditions, e.g., at 25 0 C to fit into the introducer instrument for insertion into the vascular malformations (such as an aneurysm sac or endoloeak nexus within the sac).
  • an implant may be supplied to the medical practitioner performing the implantation operation, in a compressed configuration, for example, contained in a package, preferably a sterile package.
  • the resiliency of the elastomeric matrix that is used to fabricate the implant causes it to recover to a working size and configuration in situ, at the implantation site, after being released from its compressed state within the introducer instrument.
  • the working size and shape or configuration can be substantially similar to original size and shape after the in situ recovery.
  • Preferred scaffolds are reticulated elastomeric polymeric materials having sufficient structural integrity and durability to endure the intended biological environment, for the intended period of implantation.
  • at least partially hydrophobic polymeric scaffold materials are preferred although other materials may be employed if they meet the requirements described herein.
  • Useful materials are preferably elastomeric in that they can be compressed and can resiliently recover to substantially the pre-compression state.
  • Alternative reticulated polymeric materials with interconnected pores or networks of pores that permit biological fluids to have ready access throughout the interior of an implant may be employed, for example, woven or uonwoven fabrics or networked composites of microstructural elements of various forms.
  • a partially hydrophobic scaffold is preferably constructed of a material selected to be sufficiently biodurable, for the intended period of implantation that the implant will not lose its structural integrity during the implantation time in a biological environment.
  • the biodurable elastomeric matrices forming the scaffold do not exhibit significant symptoms of breakdown, degradation, erosion or significant deterioration of mechanical properties relevant to their use when exposed to biological environments and/or bodily stresses for periods of time commensurate with the use of the implantable device.
  • the desired period of exposure is to be understood to be at least 29 days, preferably several weeks and most preferably 2 to 5 years or more. This measure is intended to avoid scaffold materials that may decompose or degrade into fragments, for example, fragments that could have undesirable effects such as causing an unwanted tissue response.
  • the void phase, preferably continuous and interconnected, of the reticulated polymeric matrix that is used to fabricate the implant of this invention may comprise as little as 50% by volume of the elastomeric matrix, referring to the volume provided by the interstitial spaces of elastomeric matrix before any optional interior pore surface coating or layering is applied.
  • the volume of void phase as just defined is from about 70% to about 99% of the volume of elastomeric matrix.
  • the volume of void phase is from about 80% to about 98% of the volume of elastomeric matrix.
  • the volume of void phase is from about 90% to about 98% of the volume of elastomeric matrix.
  • a pore when a pore is spherical or substantially spherical, its largest transverse dimension is equivalent to the diameter of the pore.
  • a pore when a pore is non-spherical, for example, ellipsoidal or tetrahedral, its largest transverse dimension is equivalent to the greatest distance within the pore from one pore surface to another, e.g., the major axis length for an ellipsoidal pore or the length of the longest side for a tetrahedral pore.
  • the major axis length for an ellipsoidal pore or the length of the longest side for a tetrahedral pore For those skilled in the art, one can routinely estimate the pore frequency from the average cell diameter in microns.
  • the average diameter or other largest transverse dimension of pores is at least about 50 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 100 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 150 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 250 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than about 250 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than about 250 ⁇ m.
  • the average diameter or other largest transverse dimension of pores is at least about 275 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than about 275 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than 275 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 300 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than about 300 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than 300 ⁇ m. In one embodiment the reticulated biodurable elastomeric matrix can have a larger dimension of from about 1 to about 100 mm optionally from about 3 to 50 mm, when a plurality of relatively small implants is employed.
  • the average diameter or other largest transverse dimension of pores is not greater than about 900 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 850 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 800 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 700 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 600 ⁇ m. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 500 ⁇ m.
  • the reticulated polymeric matrix that is used to fabricate the implants of this invention has any suitable bulk density, also known as specific gravity, consistent with its other properties.
  • the bulk density may be from about 0.005 to about 0.15 g/cc (from about 0.31 to about 9.4 lb/ft 3 ), preferably from about 0.015 to about 0.115 g/cc (from about 0.93 to about 7.2 lb/ft 3 ) and most preferably from about 0.024 to about 0.104 g/cc (from about 1.5 to about 6.5 lb/ft 3 ).
  • the reticulated elastomeric matrix has sufficient tensile strength such that it can withstand normal manual or mechanical handling during its intended application and during post-processing steps that may be required or desired without teaiing, breaking, crumbling, fragmenting or otherwise disintegrating, shedding pieces or particles, or otherwise losing its structural integrity.
  • the tensile strength of the starting material(s) should not be so high as to interfere with the fabrication or other processing of elastomeric matrix.
  • the reticulated polymeric matrix that is used to fabricate the implants of this invention may have a tensile strength of from about 700 to about 52,500 kg/m 2 (from about 1 to about 75 psi).
  • elastomeric matrix may have a tensile strength of from about 7000 to about 28,000 kg/m 2 (from about 10 to about 40 psi). Sufficient ultimate tensile elongation is also desirable.
  • reticulated elastomeric matrix has an ultimate tensile elongation of at least about 50% to at least about 500%.
  • reticulated elastomeric matrix has an ultimate tensile elongation of at least 75% to at least about 300%.
  • One embodiment for use in the practice of the invention is a reticulated elastomeric implant which is sufficiently flexible and resilient, i.e., resiliently- compressible, to enable it to be initially compressed under ambient conditions, e.g., at 25 0 C, from a relaxed configuration to a first, compact configuration for delivery via a delivery-device, e.g., catheter, endoscope, syringe, cystoscope, trocar or other suitable introducer instrument, for delivery in vitro and, thereafter, to expand to a second, working configuration in situ.
  • a delivery-device e.g., catheter, endoscope, syringe, cystoscope, trocar or other suitable introducer instrument
  • an elastomeric matrix has the herein described resilient-compressibility after being compressed about 5-95% of an original dimension (e.g., compressed about 19/20th - l/20th of an original dimension). In another embodiment, an elastomeric matrix has the herein described resilient-compressibility after being compressed about 10-90% of an original dimension (e.g., compressed about 9/1 Oth - 1/1 Oth of an original dimension).
  • elastomeric implant has "resilient-compressibility", i.e., is “resiliently- compressible", when the second, working configuration, in vitro, is at least about 50% of the size of the relaxed configuration in at least one dimension.
  • the resilient-compressibility of elastomeric implant is such that the second, working configuration, in vitro, is at least about 80% of the size of the relaxed configuration in at least one dimension. In another embodiment, the resilient- compressibility of elastomeric implant is such that the second, working configuration, in vitro, is at least about 90% of the size of the relaxed configuration in at least one dimension. In another embodiment, the resilient-compressibility of elastomeric implant is such that the second, working configuration, in vitro, is at least about 97% of the size of the relaxed configuration in at least one dimension.
  • an elastomeric matrix has the herein described resilient-compressibility after being compressed about 5-95% of its original volume (e.g., compressed about 19/20th - l/20th of its original volume). In another embodiment, an elastomeric matrix has the herein described resilient-compressibility after being compressed about 10-90% of its original volume (e.g., compressed about 9/1 Oth - 1/1 Oth of its original volume). As used herein, "volume” is the volume swept-out by the outermost three-dimensional contour of the elastomeric matrix. In another embodiment, the resilient-compressibility of elastomeric implant is such that the second, working configuration, in vivo, is at least about 50% of the volume occupied by the relaxed configuration.
  • the resilient- compressibility of elastomeric implant is such that the second, working configuration, in vivo, is at least about 80% of the volume occupied by the relaxed configuration. In another embodiment, the resilient-compressibility of elastomeric implant is such that the second, working configuration, in vivo, is at least about 90% of the volume occupied by the relaxed configuration. In another embodiment, the resilient- compressibility of elastomeric implant is such that the second, working configuration, in vivo, occupies at least about 97% of the of volume occupied by the elastomeric matrix in its relaxed configuration.
  • reticulated elastomeric matrix that is used to fabricate the implants of this invention has a compressive strength of from about 700 to about 70,000 kg/m 2 (from about 1 to about 100 psi) at 50% compression strain. In another embodiment, reticulated elastomeric matrix has a compressive strength of from about 1,400 to about 105,000 kg/m 2 (from about 2 to about 150 psi) at 75% compression strain. [00115] In another embodiment, reticulated elastomeric matrix that is used to fabricate the implants of this invention has a compression set, when compressed to 50% of its thickness at about 25 0 C, of not more than about 30%.
  • elastomeric matrix has a compression set of not more than about 20%. In another embodiment, elastomeric matrix has a compression set of not more than about 10%. In another embodiment, elastomeric matrix has a compression set of not more than about 5%.
  • reticulated elastomeric matrix that is used to fabricate the implants of this invention has a tear strength, of from about 0.18 to about 1.78 kg/linear cm (from about 1 to about 10 lbs/linear inch).
  • the reticulated elastomeric matrix that is used to fabricate the implant can be readily permeable to liquids, permitting flow of liquids, including blood, through the composite device of the invention.
  • the water permeability of the reticulated elastomeric matrix is from about 50 l/min./psi/cm 2 to about 500 l/min./psi/cm 2 , preferably from about 100 l/min./psi/cm 2 to about 300 l/min./psi/cm 2 .
  • permeability of the unreticulated elastomeric matrix is below about 1 l/min./psi/cm 2 .
  • the permeability of the unretriculated elastomeric amtrix is below about 5 l/min./psi/cm 2 .
  • suitable biodurable reticulated elastomeric partially hydrophobic polymeric matrix that is used to fabricate the implant of this invention or for use as scaffold material for the implant in the practice of the present invention, in one embodiment sufficiently well characterized, comprise elastomers that have or can be formulated with the desirable mechanical properties described in the present specification and have a chemistry favorable to biodurability such that they provide a reasonable expectation of adequate biodurability.
  • Various biodurable reticulated hydrophobic polyurethane materials are suitable for this purpose.
  • structural materials for the inventive reticulated elastomers are synthetic polymers, especially, but not exclusively, elastomeric polymers that are resistant to biological degradation, for example, polycarbonate polyurethane-urea, polycarbonate polyurea-urethane, polycarbonate polyurethane, polycarbonate polysiloxane polyurethane, and polysiloxane polyurethane, and the like.
  • elastomers are generally hydrophobic but, pursuant to the invention, may be treated to have surfaces that are less hydrophobic or somewhat hydrophilic. In another embodiment, such elastomers may be produced with surfaces that are less hydrophobic or somewhat hydrophilic.
  • the invention can employ, for implanting, a biodurable reticulatable elastomeric partially hydrophobic polymeric scaffold material or matrix for fabricating the implant or a material. More particularly, in one embodiment, the invention provides a biodurable elastomeric polyurethane scaffold material or matrix which is made by synthesizing the scaffold material or matrix preferably from a polycarbonate polyol component and an isocyanate component by polymerization, cross-linking and foaming, thereby forming pores, followed by reticulation of the porous material to provide a biodurable reticulated elastomeric product with interconnected and/or inter-communicating pores and channels.
  • the product is designated as a polycarbonate polyurethane, being a polymer comprising urethane groups formed from, e.g., the hydroxyl groups of the polycarbonate polyol component and the isocyanate groups of the isocyanate component.
  • the invention provides a biodurable elastomeric polyurethane scaffold material or matrix which is made by synthesizing the scaffold material or matrix preferably from a polycarbonate polyol component and an isocyanate component by polymerization, cross-linking and foaming, thereby forming pores, and using water as a blowing agent and/or foaming agent during the synthesis, followed by reticulation of the porous material to provide a biodurable reticulated elastomeric product with inter-connected and/or inter-communicating pores and channels.
  • This product is designated as a polycarbonate polyurethane-urea or polycarbonate polyurea-urethane, being a polymer comprising urethane groups formed from, e.g., the hydroxy! groups of the polycarbonate polyol component and the isocyanate groups of the isocyanate component and also comprising urea groups formed from reaction of water with the isocyanate groups.
  • the process employs controlled chemistry to provide a reticulated elastomeric matrix or product with good biodurability characteristics.
  • the matrix or product employing chemistry that avoids biologically undesirable or nocuous constituents therein.
  • the starting material for synthesizing the biodurable reticulated elastomeric partially hydrophobic polymeric matrix contains at least one polyol component to provide the so-called soft segement.
  • polyol component includes molecules comprising, on the average, about 2 hydroxyl groups per molecule, i.e., a difunctional polyol or a diol, as well as those molecules comprising, on the average, greater than about 2 hydroxyl groups per molecule, i.e., a polyol or a multi-functional polyol.
  • this soft segment polyol is terminated with hydroxyl groups, either primary or secondary.
  • Exemplary polyols can comprise, on the average, from about 2 to about 5 hydroxyl groups per molecule.
  • the process employs a difunctional polyol comp'onent in which the hydroxyl group functionality of the diol is about 2.
  • the soft segment is composed of a polyol component that is generally of a relatively low molecular weight, typically from about 500 to about 6,000 daltons and preferably between 1000 to 2500 daltons.
  • the starting material for synthesizing the biodurable reticulated elastomeric partially hydrophobic polymeric matrix contains at least one isocyanate component and, optionally, at least one chain extender component to provide the so-called "hard segment".
  • the starting material for synthesizing the biodurable reticulated elastomeric partially hydrophobic polymeric matrix contains at least one isocyanate component.
  • isocyanate component includes molecules comprising, on the average, about 2 isocyanate groups per molecule as well as those molecules comprising, on the average, greater than about 2 isocyanate groups per molecule.
  • the isocyanate groups of the isocyanate component are reactive with reactive hydrogen groups of the other ingredients, e.g., with hydrogen bonded to oxygen in hydroxyl groups and with hydrogen bonded to nitrogen in amine groups of the polyol component, chain extender, crosslinker and/or water.
  • the average number of isocyanate groups per molecule in the isocyanate component is about 2.
  • the average number of isocyanate groups per molecule in the isocyanate component is greater than about 2 is greater than 2.
  • a small quantity of an optional ingredient such as a multi-functional hydroxyl compound or other cross-linker having a functionality greater than 2, is present to allow crosslinking and / or to achieve a stable foam, i.e., a foam that does not collapse to become non-foamlike.
  • polyfunctional adducts of aliphatic and cycloaliphatic isocyanates can be used to impart cross-linking in combination with aromatic diisocyanates.
  • polyfunctional adducts of aliphatic and cycloaliphatic isocyanates can be used to impart cross-linking in combination with aliphatic diisocyanates.
  • Exemplary diisocyanates include aliphatic diisocyanates, isocyanates comprising aromatic groups, the so-called “aromatic diisocyanates", and mixtures thereof.
  • Aliphatic diisocyanates include tetramethylene diisocyanate, cyclohexane- 1,2-diisocyanate, cyclohexane-l,4-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, methylene-bis-(p-cyclohexyl isocyanate) ("H 12 MDI”), and mixtures thereof.
  • Aromatic diisocyanates include p-phenylene diisocyanate, 4,4'- diphenylmethane diisocyanate (“4,4'-MDI”), 2,4'-diphenylmethane diisocyanate (“2,4'-MDI”), polymeric MDI, and mixtures thereof.
  • optional chain extenders include diols, diamines, alkanol amines or a mixture thereof.
  • the starting material for synthesizing the biodurable reticulated elastomeric partially hydrophobic polymeric matrix contains at least one blowing agent such as water.
  • blowing agents include the physical blowing agents, e.g., volatile organic chemicals such as hydrocarbons, ethanol and acetone, and various fluorocarbons, hydrofluorocarbons, chlorofluorocarbons, and hydrochlorofluorocarbons.
  • the hard segments also contain a urea component formed during foaming reaction with water.
  • the reaction of water with an isocyanate group yields carbon dioxide, which serves as a blowing agent.
  • the amount of blowing agent e.g., water, is adjusted to obtain different densities of non-reticulated foams. A reduced amount of blowing agent such as water may reduce the number of urea linkages in the material.
  • implantable device can be rendered radiopaque to facilitate in vivo imaging, for example, by adhering to, covalently bonding to and/or incorporating into the elastomeric matrix itself particles of a radio-opaque material.
  • Radio-opaque materials include titanium, tantalum, tungsten, barium sulfate or other suitable material known to those skilled in the art.
  • the starting material of -the biodurable reticulated elastomeric partially hydrophobic polymeric matrix is a commercial polyurethane polymers are linear, not crosslinked, polymers, therefore, they are soluble, can be melted, readily analyzable and readily characterizable.
  • the starting polymer provides good biodurability characteristics.
  • the reticulated elastomeric matrix is produced by taking a solution of the commercial polymer such as polyurethane and charging it into a mold that has been fabricated with surfaces defining a microstructural configuration for the final implant or scaffold, solidifying the polymeric material and removing the sacrificial mold by melting, dissolving or subliming-away the sacrificial mold.
  • the matrix or product employing a foaming process that avoids biologically undesirable or nocuous constituents therein.
  • thermoplastic elastomers such as polyurethanes whose chemistry is associated with good biodurability properties, for example.
  • thermoplastic polyurethane elastomers include polycarbonate polyurethanes, polysiloxane polyurethanes, polyurethanes with so-called "mixed" soft segments, and mixtures thereof.
  • Mixed soft segment polyurethanes are known to those skilled in the art and include, e.g., polycarbonate-polysiloxane polyurethanes.
  • thermoplastic polyurethane elastomer comprises at least one diisocyanate in the isocyanate component, at least one chain extender and at least one diol, and may be formed from any combination of the diisocyanates, difunctional chain extenders and diols described in detail above.
  • suitable thermoplastic polyurethanes for practicing the invention include: polyurethanes with mixed soft segments comprising polysiloxane together with a polycarbonate component.
  • the weight average molecular weight of the thermoplastic elastomer is from about 30,000 to about 500,000 Daltons. In another embodiment, the weight average molecular weight of the thermoplastic elastomer is from about 50,000 to about 250,000 Daltons.
  • Some commercially-available thermoplastic elastomers suitable for use in practicing the present invention include the line of polycarbonate polyurethanes supplied under the trademark BIONATE® by The Polymer Technology Group Inc. (Berkeley, CA).
  • the very well-characterized grades of polycarbonate polyurethane polymer BIONATE® 80A, 55 and 90 are soluble in THF, DMF, DMAT, DMSO, or a mixture of two or more thereof, processable, reportedly have good mechanical properties, lack cytotoxicity, lack mutagenicity, lack carcinogenicity and are non-hemolytic.
  • Another commercially-available elastomer suitable for use in practicing the present invention is the CHRONOFLEX® C line of biodurable medical grade polycarbonate aromatic polyurethane thermoplastic elastomers available from CardioTech International, Inc. (Woburn, MA).
  • the reticulated elastomeric implants or implants for packing the aneurysm sac or for other vascular occlusion can be rendered radiopaque to allow for visualization of the implants in situ by the clinician during and after the procedure, employing radioimaging.
  • Any suitable radiopaque agent that can be covalently bound, adhered or otherwise attached to the reticulated polymeric implants may be employed including without limitation, tantalum and barium sulfate.
  • a further embodiment of the invention encompasses the use of radiopaque metallic components to impart radiopacity to the implant.
  • thin filaments comprised of metals with shape memory properties such as platinum or nitinol can be embedded into the implant and may be in the form of a straight or curved wire, helical or coil-like structure, umbrella structure, or other structure generally known to those skilled in the art.
  • a metallic frame around the implant may also be used to impart radiopacity.
  • the metallic frame may be in the form of a tubular structure similar to a stent, a helical or coil-like structure, an umbrella structure, or other structure generally known to those skilled in the art. Attachment of radiopaque metallic components to the implant can be accomplished by means including but not limited to chemical bonding or adhesion, suturing, pressure fitting, compression fitting, and other physical methods.
  • Some optional embodiments of the invention comprise apparatus or devices and treatment methods employing biodurable reticulated elastomeric implants 36 into which biologically active agents are incorporated for the matrix to be used for controlled release of pharmaceutically-active agents, such as a drug, and for other medical applications.
  • Any suitable agents may be employed as will be apparent to those skilled in the art, including, for example, but without limitation thrombogenic agents, e.g., thrombin, anti-inflammatory agents, and other therapeutic agents that may be used for the treatment of abdominal aortic aneurysms.
  • the invention includes embodiments wherein the reticulated elastomeric material of the implants is employed as a drug delivery platform for localized administration of biologically active agents into the aneurysm sac. Such materials may optionally be secured to the interior surfaces of elastomeric matrix directly or through a coating.
  • the controllable characteristics of the implants are selected to promote a constant rate of drug release during the intended period of implantation.
  • pharmaceutically-active agents e.g., a drug, or other biologically useful materials.
  • the pores of biodurable reticulated elastomeric matrix that are used to fabricate the implants of this invention are coated or filled with a cellular ingrowth promoter.
  • the promoter can be foamed.
  • the promoter can be present as a film.
  • the promoter can be a biodegradable material to promote cellular invasion of pores biodurable reticulated elastomeric matrix that are used to fabricate the implants of this invention in vivo.
  • Promoters include naturally occurring materials that can be enzymatically degraded in the human body or are hydrolytically unstable in the human body, such as fibrin, fibrinogen, collagen, elastin, hyaluronic acid and absorbable biocompatible polysaccharides, such as chitosan, starch, fatty acids (and esters thereof), glucoso-glycans and hyaluronic acid.
  • the pore surface of the biodurable reticulated elastomeric matrix that are used to fabricate the implants of this invention is coated or impregnated, as described in the previous section but substituting the promoter for the biocompatible polymer or adding the promoter to the biocompatible polymer, to encourage cellular ingrowth and proliferation.
  • One possible material for use in the present invention comprises a resiliency compressible composite polyurethane material comprising a hydrophilic foam coated on and throughout the pore surfaces of a hydrophobic foam scaffold.
  • a resiliency compressible composite polyurethane material comprising a hydrophilic foam coated on and throughout the pore surfaces of a hydrophobic foam scaffold.
  • One suitable such material is the composite foam disclosed in co-pending, commonly assigned U.S. patent applications Serial No. 10/692,055, filed October 22, 2003, Serial No. 10/749,742, filed December 30, 2003, Serial No. 10/848,624, filed May 17, 2004, and Serial No. 10/900,982, filed July 27, 2004, each of which is incorporated herein by reference in its entirety.
  • the hydrophobic foam provides support and resilient compressibility enabling the desired collapsing of the implant for delivery and reconstitution in situ.
  • agents that can aid in the healing of the aneurysm such as elastin, collagen or other growth factors that will foster fibroblast proliferation and ingrowth into the aneurysm
  • agents to render the foam implant non-thrombogenic or inflammatory chemicals to foster scarring of the aneurysm.
  • the hydrophilic foam, or other agent immobilizing means can be used to carry genetic therapies, e.g. for replacement of missing enzymes, to treat atherosclerotic plaques at a local level, and to release agents such as antioxidants to help combat known risk factors of aneury
  • the pore surfaces may employ other means besides a hydrophilic foam to secure desired treatment agents to the hydrophobic foam scaffold.
  • the agents contained within the implant can provide an inflammatory response within the aneurysm, causing the walls of the aneurysm to scar and thicken. This can be accomplished using any suitable inflammation inducing chemicals, such as sclerosants like sodium tetradecyl sulphate (STS), polyiodinated iodine, hypertonic saline or other hypertonic salt solution. Additionally, the implant can contain factors that will induce fibroblast proliferation, such as growth factors, tumor necrosis factor and cytokines.
  • STS sodium tetradecyl sulphate
  • the implant can contain factors that will induce fibroblast proliferation, such as growth factors, tumor necrosis factor and cytokines.
  • the aromatic isocyanate RUBINATE 9258 (from Huntsman) was used as the isocyanate component.
  • a diol, poly(l,6-hexanecarbonate)diol (POLY-CD CD220 from Arch Chemicals) with a molecular weight of about 2,000 Daltons was used as the polyol component and was a solid at 25 0 C. Distilled water was used as the blowing agent.
  • the blowing catalyst used was the tertiary amine triethylenediamine (33% in dipropylene glycol; DABCO 33LV from Air Products).
  • a silicone-based surfactant was used (TEGOSTAB® BF 2370 from Goldschmidt).
  • a cell-opener was used (ORTEGOL® 501 from Goldschmidt).
  • the viscosity modifier propylene carbonate was present to reduce the viscosity. The proportions of the components that were used are set forth in the following table:
  • the polyol component was liquefied at 7O 0 C in a circulating-air oven, and 100 g thereof was weighed out into a polyethylene cup. 5.8 g of viscosity modifier was added to the polyol component to reduce the viscosity, and the ingredients were mixed at 3100 rpm for 15 seconds with the mixing shaft of a drill mixer to form "Mix-1". 0.66 g of surfactant was added to Mix-1, and the ingredients were mixed as described above for 15 seconds to form "Mix-2". Thereafter, 1.00 g of cell opener was added to Mix-2, and the ingredients were mixed as described above for 15 seconds to form "Mix-3". 47.25 g of isocyanate component were added to Mix-3, and the ingredients were mixed for 60 ⁇ 10 seconds to form "System A".
  • System B was poured into System A as quickly as possible while avoiding spillage.
  • the ingredients were mixed vigorously with the drill mixer as described above for 10 seconds and then poured into a 22.9 cm x 20.3 cm x 12.7 cm (9 in. x 8 in. x 5 in.) cardboard box with its inside surfaces covered by aluminum foil.
  • the foaming profile was as follows: 10 seconds mixing time, 17 seconds cream time, and 85 seconds rise time.
  • the foam was placed into a circulating-air oven maintained at 100- 105 0 C for curing for from about 55 to about 60 minutes. Then, the foam was removed from the oven and cooled for 15 minutes at about 25°C. The skin was removed from each side using a band saw. Thereafter, hand pressure was applied to each side of the foam to open the cell windows. The foam was replaced into the circulating-air oven and postcured at 100-105 0 C for an additional four hours. The average pore diameter of the foam, as determined from optical microscopy observations, was greater than about 275 ⁇ m.
  • Tensile tests were conducted on samples that were cut either parallel to or perpendicular to the direction of foam rise.
  • the dog-bone shaped tensile specimens were cut from blocks of foam. Each test specimen measured about 12.5 mm thick, about 25.4 mm wide, and about 140 mm long; the gage length of each specimen was 35 mm and the gage width of each specimen was 6.5 mm.
  • Tensile properties (tensile strength and elongation at break) were measured using an INSTRON Universal Testing Instrument Model 1122 with a cross-head speed of 500 mm/mm (19.6 inches/minute). The average tensile strength perpendicular to the direction of foam rise was determined as 29.3 psi (20,630 kg/m 2 ). The elongation to break perpendicular to the direction of foam rise was determined to be 266%.
  • the measurement of the liquid flow through the material is measured in the following way using a liquid permeability apparatus or Liquid Permeaeter (Porous Materials, Inc., Ithaca, NY).
  • the foam sample was 8.5 mm in thickness and covered a hole 6.6 mm in diameter in the center of a metal plate that was placed at the bottom of the Liquid Permeaeter filled with water. Thereafter, the air pressure above the sample was increased slowly to extrude the liquid from the sample and the permeability of water through the foam was determined to be 0.11 L/min/psi/cm 2 .
  • Example 2 Reticulation of a Crosslinked Polyurethane Foam
  • Reticulation of the foam described in Example 1 was carried out by the following procedure: A block of foam measuring approximately 15.25 cm x 15.25 cm x 7.6 cm (6 in. x 6 in. x 3 in.) was placed into a pressure chamber, the doors of the chamber were closed, and an airtight seal to the surrounding atmosphere was maintained. The pressure within the chamber was reduced to below about 100 millitorr by evacuation for at least about two minutes to remove substantially all of the air in the foam. A mixture of hydrogen and oxygen gas, present at a ratio sufficient to support combustion, was charged into the chamber over a period of at least about three minutes. The gas in the chamber was then ignited by a spark plug. The ignition exploded the gas mixture within the foam. The explosion was believed to have at least partially removed many of the cell walls between adjoining pores, thereby forming a reticulated elastomeric matrix structure.
  • the average pore diameter of the reticulated elastomeric matrix was greater than about 275 ⁇ m.
  • a scanning electron micrograph image of the reticulated elastomeric matrix of this example (not shown here) demonstrated, e.g., the communication and interconnectivity of pores therein.
  • the density of the reticulated foam was determined as described above in Example 1. A post-reticulation density value of 2.83 lbs/ft 3 (0.0453 g/cc) was obtained.
  • Example 2 Tensile tests were conducted on reticulated foam samples as described above in Example 1.
  • the average post-reticulation tensile strength perpendicular to the direction of foam rise was determined as about 26.4 psi (18,560 kg/m 2 ).
  • the post- reticulation elongation to break perpendicular to the direction of foam rise was determined to be about 250%.
  • the average post-reticulation tensile strength parallel to the direction of foam rise was determined as about 43.3 psi (30,470 kg/m 2 ).
  • the post-reticulation elongation to break parallel to the direction of foam rise was determined to be about 270%.
  • Compressive tests were conducted using specimens measuring 50 mm x 50 mm x 25 mm. The tests were conducted using an INSTRON Universal Testing Instrument Model 1122 with a cross-head speed of 10 mm/min (0.4 inches /minute).
  • the post-reticulation compressive strengths at 50% compression, parallel to and perpendicular to the direction of foam rise were determined to be 1.53 psi (1,080 kg/m 2 ) and 0.95 psi (669 kg/m 2 ), respectively.
  • the post-reticulation compressive strengths at 75% compression, parallel to and perpendicular to the direction of foam rise were determined to be 3.53 psi (2,485 kg/m 2 ) and 2.02 psi (1,420 kg/m 2 ), respectively.
  • the post-reticulation compression set determined after subjecting the reticulated sample to 50% compression for 22 hours at 25 0 C then releasing the compressive stress, parallel to the direction of foam rise, was determined to be about 4.5%.
  • the resilient recovery of the reticulated foam was measured by subjecting 1 inch (25.4 mm) diameter and 0.75 inch (19 mm) long foam cylinders to 75% uniaxial compression in their length direction for 10 or 30 minutes and measuring the time required for recovery to 90% ("t-90%”) and 95% (“t-95%”) of their initial length. The percentage recovery of the initial length after 10 minutes (“r-10") was also determined. Separate samples were cut and tested with their length direction parallel to and perpendicular to the foam rise direction. The results obtained from an average of two tests are shown in the following table:
  • a comparable foam with little to no reticulation typically has t-90 values of greater than about 60-90 seconds after 10 minutes of compression.
  • the measurement of the liquid flow through the material is measured in the following way using a Liquid permeability apparatus or Liquid Permeaeter (Porous Materials, Inc., Ithaca, NY).
  • the foam samples were between 7.0 and 7.7 mm in thickness and covered a hole 8.2 mm in diameter in the center of a metal plate that was placed at the bottom of the Liquid Permeaeter filled with water.
  • the water was allowed to extrude through the sample under gravity and the permeability of water through the foam was determined to be 180 L/min/psi/cm 2 in the direction of foam rise and 160 L/min/psi/cm in the perpendicular to foam rise.
  • Example 3 Histological Evaluation of a Plurality of Crosslinked Reticulated Polyurethane Matrix Implants in a Canine Carotid Bifurcation Aneurysm Model
  • An established animal model of cerebral aneurysms was used to evaluate the histologic outcomes of implanting a plurality of cylindrical implants machined from a block of cross-linked reticulated polyurethane matrix as described in Example 2.
  • the three animals were sacrificed at the three-month timepoint to assess tissue response to the cross-linked reticulated polyurethane matrix.
  • One of two different implant configurations was used in this experiment. The first configuration was a cylindrical implant measuring 6 mm diameter x 15 mm length.
  • the second configuration was a segmented, cylindrical implant measuring 3 mm diameter x 15 mm length.
  • a rotating die cutter was used to cut 3 mm and 6 mm diameter cylinders. The implants were then trimmed to 15 mm in length. Implant dimensions were tested for acceptability by use of calipers and visualization under a stereo-microscope, with acceptance of implants measuring +/- 5% of target dimensions.
  • An aneurysm was surgically created at the carotid arterial bifurcation of three dogs. This model simulates the hemodynamics of a human saccular aneurysm, which typically occurs at an arterial bifurcation.
  • a second embolization procedure was performed in which a plurality of implants machined from a block of cross-linked reticulated polyurethane matrix was delivered into the aneurysm sac using a guide catheter.
  • the 6x15 mm cylindrical implants were delivered using a commercially available 7 Fr Cordis Vista-Brite guide catheter.
  • the 3x15 mm cylindrical implants were delivered using a commercially available 5 Fr Cordis Vista- Brite guide catheter.
  • a loader apparatus was used to pull compress the implants from their expanded state into a compressed state for introduction through the hemostasis valve of the guide catheter.
  • An obturator was then used to push the compressed implant from the proximal end of the guide catheter to the distal end, where the implant was deployed in a slow, controlled manner into the aneurysm sac.
  • the animals were sacrificed to assess tissue response to the cross-linked reticulated polyurethane matrix.
  • samples were dehydrated in a graded series of ethanol and embedded in methylmethacrylate plastic. After polymerization, each aneurysm was bisected (sawn) longitudinally by the Exakt method and glued onto a holding block for sectioning using a rotary microtome at 5 - 6 microns. The sections were mounted on charged slides and stained with hematoxylin-eosin and Movat pentaclirome stains. All sections were examined by light microscopy for the presence inflammation, healing response, calcification and integrity of the wall at the neck interface and surrounding aneurysm.
  • the histological response to the reticulated polyurethane matrix in this experiment demonstrated that the material can serve as a scaffold to support extensive organic tissue ingrowth with minimal inflammation and thereby holds promise as a bioactive solution to the treatment of cerebral aneurysms.
  • Neurostring implants To create the Neurostring implants, thin sheets measuring 2.0 mm in depth were sliced from a block of reticulated polyurethane matrix. A sewing machine was then used to stitch surgical suture measuring 0.003" in diameter through the thin foam sheet to form a straight line. Individual strings were cut by using micro-scissors to trim around the suture line under a microscope until the final outer diameter of 0.030" (outside edge of the foam string) was achieved. Neurostring implant dimensions were tested for acceptability by delivering each individual string through a custom-made 3.5F (0.035" inner diameter) microcatheter. Platinum bands were hand-crimped every 1.0 cm along the length of each neurostring implants to impart radiopacity.
  • An aneurysm was surgically created at the carotid arterial bifurcation of three dogs. This model simulates the hemodynamics of a human saccular aneurysm, which typically occurs at an arterial bifurcation.
  • a second embolization procedure was performed as follows. After preparing the access site using standard surgical technique, a 6F Boston Scientific Guide Catheter with Straight Tip was advanced to the aneurysm. A Boston Scientific Excelsior 3F Microcatheter was then advanced through the guide catheter into the aneurysm neck. One or two GDC- 18 framing coils were then deployed through the microcatheter to frame the aneurysm. After positioning and detaching the framing coil, the Excelsior microcatheter was withdrawn.
  • a custom-made 3.5F (0.035" inner diameter) microcatheter was then advanced through the guide catheter into the aneurysm neck.
  • the Neurostring implant, loader, and pusher wire were removed from their sterile packaging.
  • the loaded Neurostring implant and microcatheter were flushed with sterile saline.
  • the loader/Neurostring implant was then introduced into the hemostasis valve of the microcatheter.
  • the Neurostring implant was subsequently delivered into the aneurysm by pushing the implant with the pusher wire while using hydraulic assistance through the 3.5F custom microcatheter.
  • the Neurostring implant was positioned and detached into the aneurysm.
  • the pusher wire was removed from the microcatheter and an angiogram was performed to confirm occlusion. Neurostring implants ranging from 10 - 18 cm in length were deployed as necessary until angiographic occlusion was confirmed.
  • Table 4 shows the quantities and volumes of framing coils and Neurostring implants used in each of the three animals. All 22 Neurostring implants were successfully delivered using hydraulic assistance and controlled mechanical detachment. Post-procedure angiographic occlusion was achieved in all three animals, with minor neck remnants.
  • an angiogram was performed to assess angiographic outcomes including device stability (compaction) and aneurysm recanalization. All three dogs showed stable or progressing occlusion with no device compaction and no evidence of aneurysm recanalization.
  • the angiographic series from BMX-5 is shown in Figures 27A to 27B, where Figure 27A represents pre-embolization, Figure 27B reoresents ⁇ ost embolization, and Fieure 27C renresents follow-uD.
  • the angiographic outcomes at two-week followup demonstrated that Neurostring implants can be utilized for the embolization of cerebral aneurysms. This experiment showed the Neurostring device is consistently deliverable through a 3F microcatheter, and that the Neurostring implants are stable with no evidence of device compaction, no migration, and no aneurysm recanalization at the two-week followup timepoint.
  • Table 6 shows that packing densities ranging from 40% - 350% result in angiographic occlusion at two-week followup with stable or progressing occlusion and no device compaction.
  • the one exception, BMX-I was noted to occur in a dog with an unusual, giant, unstable aneurysm that continued to expand even at the two-week angiographic followup timepoint.

Abstract

An aneurysm treatment device for in situ treatment of aneurysms comprises a collapsible member having a first shape wherein the first shape is an expanded geometric configuration, and a second shape, wherein the second shape is a collapsed configuration that is loadable into a catheter. The aneurysm treatment device is capable of returning to the first shape in the sac of an aneurysm upon deployment, where it occludes the aneurysm. In another embodiment an occlusion device comprises a flexible, longitudinally extending elastomeric matrix member that assumes a non-linear shape to conformally fill a targeted vascular site.

Description

ANEURYSM TREATMENT DEVICES AND METHODS
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of co-pending, commonly assigned U.S. patent application Serial No. 10/998,357, filed November 26, 2004, co-pending, commonly assigned U.S. patent application Serial No. 11/111,487, filed April 21, 2005, and co-pending, commonly assigned U.S. patent application Serial No. 11/229,044, filed September 15, 2005, each of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to methods and devices for the treatment of vascular aneurysms and other comparable vascular abnormalities. More particularly, this invention relates to occlusion devices for vascular aneurysms that comprise a reticulated elastomeric matrix structure and a delivery device.
BACKGROUND OF THE INVENTION
[0003] The cardio-vascular system, when functioning properly, supplies nutrients to all parts of the body and carries waste products away from these parts for elimination. It is essentially a closed-system comprising the heart, a pump that supplies pressure to move blood through the blood vessels, blood vessels that lead away from the heart, called arteries, and blood vessels that return blood toward the heart, called veins. On the discharge side of the heart is a large blood vessel called the aorta from which branch many arteries leading to all parts of the body, including the organs. As the arteries get close to the areas they serve, they dimmish to small arteries, still smaller arteries called arterioles, and ultimately connect to capillaries. Capillaries are minute vessels where outward diffusion of nutrients, including oxygen, and inward diffusion of wastes, including carbon dioxide, takes place. Capillaries connect to tiny veins called venules.
[0004] Venules in turn connect to larger veins which return the blood to the heart by way of a pair of large blood vessels called the inferior and superior venae cava.
[0005] As shown in Figure 1, arteries 2 and veins comprise three layers known as tunics. An inner layer 4, called the tunica interna, is thin and smooth, constituted of endothelium, and rests on a connective tissue membrane rich in elastic and collagenous fibers that secrete biochemicals to perform functions such as prevention of blood clotting by inhibiting platelet aggregation and regulation of vasoconstriction and vasodilation. A middle layer 6 called the tunica media is made of smooth muscle 8 and elastic connective tissue 10 and provides most of the girth of the blood vessel. A thin outer layer 12, called the tunica adventitia, formed of connective tissue secures the blood vessel to the surrounding tissue.
[0006] The tunica media 6 differentiates an artery from a vein in that it is thicker in an artery to withstand the higher blood pressure exerted by the heart on the walls of the arteries. Tough elastic connective tissue provides an artery 2 sufficient elasticity to withstand the blood pressure and sudden increases in blood volume that occur with ventricular contractions.
[0007] When the wall of an artery, especially the tunica media 6 of that wall, has a weakness, the blood pressure can dilate or expand the region of the artery 2 with the weakness, and a pulsating sac 14 called a berry or saccular aneurysm (Figure 2), can develop. If the walls of the arteries 2 expand around the circumference of the artery 2, this is called a fusiform aneurysm 16 (Figure 3). If the weakness causes a longitudinal tear in the tunica media of the artery, it is called a dissecting aneurysm. Saccular aneurysms are common at artery bifurcations 18 (Figures 4 and 5) located around the brain. Dissecting aneurysms are common in the thoracic and abdominal aortas. The pressure of an aneurysm against surrounding tissues, especially the pulsations, may cause pain and may also cause tissue damage. However, aneurysms are often asymptomatic. The blood in the vicinity of the aneurysm can become turbulent, leading to formation of blood clots, that may be carried to various body organs where they may cause damage in varying degrees, including cerebrovascular incidents, myocardial infarctions and pulmonary embolisms. Should an aneurysm tear and begin to leak blood, the condition can become life threatening, sometimes being quickly fatal, in a matter of minutes.
[0008] Because there is relatively little blood pressure in a vein, venous
"aneurysms" are non-existent. Therefore, the description of the present invention is related to arteries, but applications within a vein, if useful, are to be understood to be within the scope of this invention.
[0009] The causes of aneurysms are still under investigation. However, researchers have identified a gene associated with a weakness in the connective tissue of blood vessels that can lead to an aneurysm. Additional risk factors associated with aneurysms such as hyperlipidemia, atherosclerosis, fatty diet, elevated blood pressure, smoking, trauma, certain infections, certain genetic disorders, such as Marfan' s Syndrome, obesity, and lack of exercise have also been identified. Cerebral aneurysms, frequently occur in otherwise healthy and relatively youthful people and have been associated with many untimely deaths.
[0010] Aneurysms, widening of arteries caused by blood pressure acting on a weakened arterial wall, have occurred ever since humans walked the planet. In recent times, many methods have been proposed to treat aneurysms. _For example, Greene, Jr., et al., in U.S. Patent No. 6,165,193 propose a vascular implant formed of a compressible foam hydrogel that has a compressed configuration from which it is expansible into a configuration substantially conforming to the shape and size of a vascular malformation to be embolized. Greene's hydrogel lacks the mechanical properties to enable it to regain its size and shape in vivo were it to be compressed for catheter, endoscope, or syringe delivery, and the process can be complex and difficult to implement. Other patents disclose introduction of a device, such as a stent or balloon (Naglreiter et al., U.S. Patent No. 6,379,329) into the aneurysm, followed by introduction of a hydrogel in the area of the stent to attempt to repair the defect (Sawhney et al., U.S. Patent No. 6,379,373).
[0011] Still other patents suggest the introduction into the aneurysm of a device, such as a stent, having a coating of a drug or other bioactive material (Gregory, U.S. Patent No. 6,372,228). Other methods include attempting to repair an aneurysm by introducing via a catheter a self-hardening or self-curing material into the aneurysm. Once the material cures or polymerizes in situ into a foam plug, the vessel can be recanalized by placing a lumen through the plug (Hastings, U.S. Patent No. 5,725,568).
[0012] Another group of patents relates more specifically to saccular aneurysms and teaches the introduction of a device, such as string, wire or coiled material (Boock U.S. Patent No. 6,312,421), or a braided bag of fibers (Greenhalgh, U.S. Patent No. 6,346,117) into the lumen of the aneurysm to fill the void within the aneurysm. The device introduced can carry hydrogel, drugs or other bioactive materials to stabilize or reinforce the aneurysm (Greene Jr. et al., U.S. Patent No. 6,299,619).
[0013] Another treatment known to the art comprises catheter delivery of platinum microcoils into the aneurysm cavity in conjunction with an embolizing composition comprising a biocompatible polymer and a biocompatible solvent. The deposited coils or other non-particulate agents are said to act as a lattice about which a polymer precipitate grows thereby embolizing the blood vessel (Evans et al., U.S. Patent No. 6,335,384).
[0014] It is an understanding of the present invention that such methods and devices suffer a variety of problems. For example, if an aneurysm treatment is to be successful, any implanted device must be present in the body for a long period of time, and must therefore be resistant to rejection, and not degrade into materials that cause adverse side effects. While platinum coils may be having some benefits in this respect, they are inherently expensive, and the pulsation of blood around the aneurysm may cause difficulties such as migration of the coils, incomplete sealing of the aneurysm, or fragmentation of blood clots. It is also well known that the use of a coil is frequently associated with recanalization of the site, leading to full or partial reversal of the occlusion. If the implant does not fully occlude the aneurysm and effectively seal against the aneurysm wall, pulsating blood may seep around the implant and the distended blood vessel wall causing the aneurysm to reform around the implant.
[0015] The delivery mechanics of many of the known aneurysm treatment methods can be difficult, challenging, and time consuming.
[0016] Most contemporary vascular occlusion devices, such as coils, thrombin, glue, hydrogels, etc., have serious limitations or drawbacks, including, but not limited to, early or late recanalization, incorrect placement or positioning, migration, and lack of tissue ingrowth and biological integration. Also, some of the devices are physiologically unacceptable and engender unacceptable foreign body reactions or rejection. In light of the drawbacks of the known devices and methods, there is a need for more effective aneurysm treatment that produces permanent biological occlusion, can be delivered in a compressed state through small diameter catheters to a target vascular or other site with minimal risk of migration, will prevent the aneurysm from leaking or reforming.
OBJECTS OF THE INVENTION
[0017] It is an object of this invention to provide a method and device for the treatment of vascular aneurysms.
[0018] It is also an object of this invention to provide a method and device for occluding cerebral aneurysms.
[0019] It is a further object of the invention to provide a method and device for occluding cerebral aneurysms by bio-integrating and sealing off the aneurysm to , prevent migration, recanalization, leaking, or reforming.
[0020] It is a yet further object of this invention to provide a method and device for occluding vascular aneurysms wherein the device comprises a reticulated elastomeric matrix structure and a delivery device.
[0021] It is a yet further object of this invention to provide a system for treating cerebral aneurysms that comprises a reticulated elastomeric matrix structure and a delivery device.
[0022] It is a yet further object of the invention to provide an implant for occluding a cerebral aneurysm that comprises a reticulated elastomeric matrix structure that compresses for delivery and expands upon deployment in an aneurysm to cause angiographic occlusion.
[0023] These and other objects of the invention will become more apparent in the discussion below.
SUMMARY OF THE INVENTION
[0024] According to the invention an aneurysm treatment device is provided for in situ treatment of aneurysms, particularly, cerebral aneurysms, in mammals, especially humans. The treatment device comprises a resiliently collapsible implant comprised of a reticulated, biodurable elastomeric matrix, which is collapsible from a first, expanded configuration wherein the implant can support the wall of an aneurysm to a second collapsed configuration wherein the collapsible implant is deliverable into the aneurysm, for example, by being loadable into a catheter and passed through the patient's vasculature. Pursuant to the invention, useful aneurysm treatment devices can have sufficient resilience, or other mechanical property, including expansion, to return to an expanded configuration within the space of the aneurysm and to occlude the aneurysm. Preferably, the implant is configured so that hydraulic forces within the aneurysm coupled with recovery and resilience characteristics of the reticulated elastomeric matrix tend to urge the implant against the aneurysm wall.
[0025] In another embodiment of the invention, an implant comprises one or more flexible, connected, preferably spherically-, ellipsoidally-, or cylindrically- shaped structures that are positioned in a compressed state in a delivery catheter. The connected structures preferably have spring coils on each end, one of which coils is releasably secured within the delivery catheter. A longitudinally extending rod or wire that acts to assist in pushing the implant distally extends through the structures and is withdrawn during delivery. The implant tends to form a spiral shape after delivery.
[0026] In another embodiment of the invention an implant that is initially essentially cylindrical in shape in connection with a delivery catheter comprises a mechanism such that when the structure is positioned at a desired location, the mechanism is engaged to cause the structure to assume any particular shape that will occlude an aneurysm. [0027] In another embodiment of the invention, an implant for occlusion of an aneurysm comprises reticulated elastomeric matrix in a shape that can be compressed, can be inserted into a delivery catheter, can be ejected or deployed from the delivery catheter into an aneurysm, and can then expand to sufficient size and shape to occlude the aneurysm. Examples of such shapes include, but are not limited to, spheres, hollow spheres, cylinders, hollow cylinders, noodles, cubes, pyramids, tetrahedrons, hollow cylinders with lateral slots, trapezoids, parallelepipeds, ellipsoids, rods, tubes, or elongated prismatic forms, folded, coiled, helical or other more compact configurations, segmented cylinders where "sausage-like" segments have been formed, flat square or rectangular shapes, daisy shapes, braided shapes, or flat spiral shapes, optionally with surgical suture or radiopaque wire support extending therein.
[0028] Although multiple implants can be deployed, used or implanted, it is a feature of one aspect of the present invention that preferably a single implant fills an aneurysm, effectively a "single shot" occlusion. It is contemplated, in one embodiment, that even when their pores become partially filled or completely filled with biological fluids, bodily fluids and/or tissue in the course of time or immediately after delivery, and/or the implants are either still partially compressed or partially recovered after delivery, such implantable device or devices for vascular malformation applications have a volume of at least about 50% of the aneurysm volume. The ratio of implant (or implants) volume to aneurysm volume is defined as packing density. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 75% of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 125 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 175% of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 200 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 300 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 400 % of the aneurysm volume.
[0029] The packing density is targeted to achieve angiographic occlusion after embolization of the aneurysm by the implant, followed by clotting, thrombosis, and tissue ingrowth, ultimately leading to biological obliteration of the aneurysm sac. Permanent tissue ingrowth will prevent any possible recanalization.
[0030] It is furthermore preferable that the implant be treated or formed of a material that will encourage such fibroblast immigration. It is also desirable that the implant be configured, with regard to its three-dimensional shape, and its size, resiliency and other physical characteristics, and be suitably chemically or biochemically constituted to foster eventual tissue ingrowth and formation of scar tissue that will help fill and/or obliterate the aneurysm sac.
[0031] The aneurysm treatment device preferably comprises a reticulated biodurable elastomeric matrix or the like that is capable of being compressed and inserted into a catheter for implantation. In another embodiment, the implant can be formed of a partially hydrophobic reticulated biodurable elastomeric matrix having its pore surfaces coated to be partially hydrophilic, for example, by being coated with at least a partially hydrophilic material, optionally a partially hydrophilic reticulated elastomeric matrix. Preferably the entire foam has such a hydrophilic coating throughout the pores of the reticulated elastomeric matrix.
[0032] In one embodiment, the hydrophilic material carries a pharmacologic agent, for example, elastin to foster fibroblast proliferation. It is also within the scope of the invention for the pharmacologic agent to include sclerotic agents, inflammatory induction agents, growth factors capable of fostering fibroblast proliferation, or genetically engineered an/or genetically acting therapeutics. The pharmacologic agent or agents preferably are dispensed over time by the implant. Incorporation of biologically active agents in the hydrophilic phase of a composite foam suitable for use in the practice of the present invention is described in co-pending, commonly assigned U.S. patent applications Serial No. 10/692,055, filed October 22, 2003, Serial No. 10/749,742, filed December 30, 2003, Serial No. 10/848,624, filed May 17, 2004, and Serial No. 10/900,982, filed July 27, 2004, each of which is incorporated herein by reference in its entirety.
[0033] In another aspect, the invention provides a method of treating an aneurysm comprising the steps of:
imaging an aneurysm to be treated to determine its size and topography;
selecting an aneurysm treatment device according to the invention for use in treating the aneurysm; and
implanting the aneurysm treatment device into the aneurysm.
[0034] Preferably, the method further comprises:
loading the aneurysm treatment device into a catheter or other delivery means;
threading the catheter through an artery to the aneurysm; and
positioning and releasing the aneurysm treatment device in the aneurysm. [0035] Once an aneurysm has been identified using suitable imaging technology, such as a magnetic resonance image (MRI), computerized tomography scan (CT Scan), x-ray imaging with contrast material or ultrasound, and is to be treated, the surgeon chooses which implant he or she feels would best suit the aneurysm, both in shape and size. The implant can be used alone. In another embodiment, the aneurysm treatment device of the invention may also be used in conjunction with a frame of platinum coils to assist in reducing or eliminating the risk of implant migration out of the neck of the aneurysm. This is particularly true in the case of wide neck or giant aneurysms. The chosen implant is then loaded into an intravascular catheter in a compressed state. If desired, the implant can be provided in a sterile package in a pre-compressed configuration, ready for loading into a catheter. Alternatively, the implants can be made available in an expanded state, also, preferably, in a sterile package, and the surgeon at the site of implantation can use a suitable secondary device or a loader apparatus to compress an implant so that it can be loaded into a delivery catheter.
[0036] With an implant loaded into the catheter, the catheter is advanced through an artery to the diseased portion of the affected artery using any suitable technique known in the art. By use of the catheter the implant is then inserted and positioned within the aneurysm. As the implant is released from the catheter, where it is in its compressed state, it expands and is manipulated into a suitable position within the aneurysm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] One or more embodiments of the invention and of making and using the invention, as well as the best mode contemplated of carrying out the invention, are described in detail below, by way of example, with reference to the accompanying drawings, in which:
[0038] Figure 1 is a side view of an artery with layers partially cut away to illustrate the anatomy of the artery;
[0039] Figure 2 is a longitudinal cross-section of an artery with a saccular aneurysm;
[0040] Figure 3 is a longitudinal cross-section of an artery with a fusiform aneurysm;
[0041] Figure 4 is a top view of an artery at a bifurcation;
[0042] Figure 5 is a top view of an artery at a bifurcation with a saccular aneurysm at the point of bifurcation;
[0043] Figures 6 to 8 illustrate an embodiment of the invention wherein a segmented vascular occlusion device is deployed;
[0044] Figures 9 and 10 illustrate a further embodiment of the invention where a vascular occlusion device is fixed in position;
[0045] Figures 11 to 24B represent embodiments of implants and delivery systems useful according to the invention;
[0046] Figures 25 and 26 represent micrographs of tissue ingrowth; and
[0047] Figures 27A to 27C represent different stages of embolization formation in a dog. DETAILED DESCRIPTION OF THE INVENTION
[0048] The present invention relates to a system and method for treating aneurysms, particularly cerebral aneurysms, in situ. As will be described in detail below, the present invention provides an aneurysm treatment device comprising a reticulated, biodurable elastomeric matrix implant designed to be permanently inserted into an aneurysm with the assistance of an intravascular catheter. Reticulated matrix, from which the implants are made, has sufficient and required liquid permeability and thus selected to permit blood, or other appropriate bodily fluid, and cells and tissues to access interior surfaces of the implants. This happens due to the presence of interconnected and inter-communicating, reticulated open pores and/or voids and/or channels that form fluid passageways or fluid permeability providing fluid access all through. The implants described in detail below can be made in a variety of sizes and shapes, the surgeon being able to choose the best size and shape to treat a patient's aneurysm. Once inserted the inventive aneurysm treatment device or implant is designed to cause angiographic occlusion, followed by clotting, thrombosis, and eventually bio-integration through tissue ingrowth and proliferation. Furthermore, the inventive aneurysm treatment device can carry one or more of a wide range of beneficial drugs and chemical moieties that can be released at the affected site for various treatments, such as to aid in healing, foster scarring of the aneurysm, prevent further damage, or reduce risk of treatment failure. With release of these drugs and chemicals locally, employing the devices and methods of the invention, their systemic side effects are reduced.
[0049] An implant or occlusion device according to the invention can comprise a reticulated biodurable elastomeric matrix or other suitable material and can be designed to be inserted into an aneurysm through a catheter. A preferred reticulated elastomeric matrix is a compressible, lightweight material, designed for its ability to expand within the aneurysm without expanding too much and tearing the aneurysm. Although multiple implants can be deployed, used or implanted, preferably a single implant should fill the aneurysm to achieve angiographic occlusion. It is contemplated, in one embodiment, that even when their pores become partially filled or completely filled with biological fluids, bodily fluids and/or tissue in the course of time or immediately after delivery, and/or the implants are either still partially compressed or partially recovered after delivery, such implantable device or devices for vascular malformation applications have a volume of at least about 50% of the aneurysm volume. The ratio of implant (or implants) volume to aneurysm volume is defined as packing density. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 75% of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 125 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 175% of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 200 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 300 % of the aneurysm volume. In another embodiment, such implantable device or devices for vascular malformation applications have a volume of at least about 400 % of the aneurysm volume. Insertion of the implant followed by tissue ingrowth should result in total obliteration of the aneurysm sac.
[0050] Employment of an implant that can support invasion of fibroblasts and other cells enables the implant to eventually become a part of the healed aneurysm. Elastin can also be coated onto the implant providing an additional route of clot formation.
[0051] The implant can also contain one or more radiopaque markers for visualization by radiography or ultrasound to determine the orientation and location of the implant within the aneurysm sac. Preferably plantinum markers are incorporated in the implant and/or relevant positions of delivery members. [0052] If desired, the outer surfaces of the implant or occlusion device can be coated, after fabrication of the implant or occlusion device with functional agents, such as those described herein, optionally employing an adjuvant that secures the functional agents to the surfaces and to reticulated elastomeric matrix pores adjacent the outer surfaces, where the agents will become quickly available. Such external coatings, which may be distinguished from internal coatings provided within and preferably throughout the pores of reticulated elastomeric matrix used, may comprise fibrin and/or other agents to promote fibroblast growth.
[0053] Once an aneurysm has been identified using suitable imaging technology, such as a magnetic resonance image (MRI), computerized tomography scan (CT Scan), x-ray imaging with contrast material or ultrasound, the surgeon chooses which implant he or she feels would best suit the aneurysm, both in shape and size. The chosen implant is then loaded into an intravascular catheter in a compressed state. The implants can be sold in a sterile package containing a pre-compressed implant that is loaded into a delivery catheter. Alternatively, the implant can be sold in a sterile package in an expanded state, and the surgeon at the site of implantation can use a device, e.g. a ring, funnel or chute that compresses the implant for loading into the catheter.
[0054] Once the implant is loaded into the catheter, the catheter is then advanced through an artery to the diseased portion of the affected artery using any of the techniques common in the art. Using the catheter the implant is then inserted and positioned within the aneurysm. Once the implant is released from its compressed state, it is allowed to expand within the aneurysm.
[0055] When properly located in situ, pursuant to the teachings of this invention, implants or occlusion devices are intended to cause angiographic occlusion of the aneurysm sac. The presence of implants or occlusion devices, optionally including one or more pharmacologic agents borne on each implant, stimulates fibroblast proliferation, growth of scar tissue around the implants and eventual immobilization of the aneurysm.
[0056] Advantageously, the implants of the invention can, if desired, comprise reticulated biodurable elastomeric implants having a materials chemistry and microstructure as described herein.
[0057] The invention can perhaps be better appreciated from the drawings. In the embodiment of the invention shown in Figures 6 to 8, a foam structure 50 comprises two or more sections 52, preferably from about 2 to about 100, that are defined by radiopaque rings, e.g., platinum rings or compression members 54 or similar mechanisms. Foam sections 52 comprise a longitudinally extending flexible mesh 58 defining a lumen 62. A distal spring section 64 attached to the distal end 66 of structure 50 comprises a distal tip 68 and a lumen 70 in communication with lumen 62. At the proximal end 74 of structure 50 a proximal spring 72 is attached to proximal end 74 and has a lumen 76 extending therethrough. A flexible but rigid wire 78 extends through lumen 76, lumen 62, and lumen 70. Wire 78 has a radiopague tip marker 60. Flexible mesh 58 extends distally as a jacket to cover coil 64 and proximally as a jacket to cover coil 72.
[0058] Compressed structure 50 is positioned within a delivery catheter 80 that has a longitudinally extending lumen 82 and a distal radiopaque marker 86. The proximal end 88 of catheter 80 has a narrowed opening 90 that slidably engages a pushing catheter 94.
[0059] The proximal end 96 of pushing catheter 94 slidably engages the proximal section 98 of wire 78. The distal end 102 of pushing catheter 94 comprises a radiopaque marker 104 and an opening 106. A flexible loop or wire 108 attached to coil 76 extends through opening 106 to engage wire 78. [0060] To deploy structure 50, as shown in Figure 7, pusher catheter 94 and wire 78 are advanced distally. As portions of structure 50 extend distally past the distal end 110 of delivery catheter 80, wire 78 is withdrawn in the proximal direction. Eventually, as shown in Figure 8, wire 78 is withdrawn past opening 106 so that flexible wire 108 releases and structure 50 is free from delivery catheter 80.
[0061] Preferably coils 70 and 76 and mesh 58 comprise a biocompatible shape memory alloy or polymer such as nitinol, so that the released structure will assume a non-linear, preferably helical or irregular, shape.
[0062] It should be appreciated that in the aspect of the invention shown in
Figure 7 the implant is still connected to the delivery "system" via connecting number 108. This is important because the implant can in this partially delivered condition be maneuvered within the patient to either reposition the implant to optimize placement allowing for a controlled delivery, or even to withdraw or retrieve the implant altogether.
[0063] Another embodiment of the invention, a shown in Figures 9 and 10, comprises a delivery catheter 130 and a vascular occlusion device 132 positioned at the distal end 134 of catheter 130. Extending within a lumen 136 of catheter 130 and through a lumen formed by a coil 138 in occlusion device 132 is a delivery member 140 that has a distal section 142, a middle section 144, and a proximal section 146. A guidewire 150 extends through lumen 152 formed within delivery member 140.
[0064] Coil 138 is wound from one single nitinol wire but it has sections with two different diameters. Coil proximal end 154 and coil distal end 156, which are like two "nuts", each have the same diameter, corresponding to and able to engage the diameter of delivery member middle section 144. The center part of coil 138 has larger a diameter, so that delivery member 140 can move through it freely. To attach occlusion device 132 in a delivery position, it needs to be stretched from a spherical or ball shape into a low profile cylindrical shape by use of a stretching device (not shown). Once device 132 is stretched, it can be locked by inserting delivery member 140 with distal section 142 and engaging proximal nut 154 and distal nut 156 by screw segment 144 to remain in a stretched position for delivery.
[0065] For deployment, occlusion device 132 can be released by rotating section 144 proximally catheter 130. As soon as section 144 unscrews from distal nut 156 into the center part of coil 138, the memory force of coil 138 will start compressing back to a sphical or ball shape, as shown in Figure 10, while section 144 moves proximally from proximal nut 154. Detachment will occur after section 144 unscrews completely from proximal nut 154 of coil 138 and soft distal tip 142 is pulled back into catheter 130. Occlusion device 132 is then released from delivery member 140 at a desired location.
[0066] Occlusion device 132 comprises shape memory metallic or polymeric members 158, preferably nitinol, to which a foam layer 160 is attached.
[0067] In Figure 11, an implant 182 is formed from a foam member 184 optionally having a round, square, ellipsoidal, or rectangular cross-section. Radiopaque, preferably platinum, markers 186 are positioned or crimped every about 2 to about 10 mm to form a chain or noodle-like structure. Implant 182 has a reinforcing filament 190 extending through the entire length of implant 182 to prevent implant 182 from breaking or fragmenting, to provide support for pulling and/or pushing during delivery or deployment, and to prevent migration during delivery or deployment. Reinforcing filament 190 can be biosorbable or non-resorbable, preferably non-resorbable, and can be comprised of a polymer such as polyester, a radiopaque metal such as platinum, or a combination thereof, including, but not limited to, known suture materials or suture composites. Moreover, reinforcing filament 190 can be a monofilament, braided rope or wire, or a wire or cable. The length of implant 182 could be from about 5 mm to about 800 mm, preferably from about 50 mm to about 600 mm, and the diameter or effective diameter could be from about 0.25 mm to about 10 mm, preferably from about 0.50 mm to about 2 mm. [0068] The implant 192 in Figure 12 comprises two or more, preferably from about 3 to 6, cylindrical or string segments 194 that are held together by a reinforcing filament (not shown) or marker 196 for structural integrity for delivery or deployment or to be blended with other components. As with implant 182, radiopaque markers 196 are crimped from about 2 to about 10 mm apart. The length and effective diameter of implant 192 are approximately the same as those of implant 182.
[0069] A preferred embodiment of an implant 200, also known as "foam on a string" or a NEUROSTRING™ implant," is shown in Figures 6 and 7. Implant 200 is formed from an elastomeric matrix member 202 having a round, square, ellipsoidal, multi-sided, polygonal, or rectangular, but preferably round, cross-section. In another embodiment, implant 200 is formed from an elastomeric matrix member 202 having an irregular shape. In yet another embodiment, the cross-section of elastomeric matrix 202 can be of regular cross-section for part of the length of implant 200 and can be of irregular cross-section for part of the length of implant 200, that is, a combination of regular cross-section and irregular cross-section. In yet another embodiment, the topology of biodurable reticulated elastomeric matrix 202 can be of regular cross-section for part of the length of implant 200 and can be of irregular cross-section for part of the length of implant 200, that is, a combination of regular cross-section and irregular cross-section. In another embodiment, matrix member 202 is biodurable and reticulated. Two longitudinally extending, essentially parallel structural filaments 204 and 206 extend the length of implant 200, and at regular intervals structural filaments 204 and 206 form knots or ropes 208 that define matrix subsections 210. A purpose of the knots is to secure the structural filament to the elastomeric matrix. This can be seen more clearly in the detail of Figure 7. Other means of incorporating filaments 204 and 206 into matrix 202 that causes similar attachment are commonly known, for example, sewing stitches. The respective ends of structural filaments 204 and 206 form a loop 212 at the proximal end 214 and optionally also distal end 216, of implant 200. [0070] Structural filaments 204 and 206 can be biosorbable or non-resorbable, preferably non-resorbable, and comprised of a polymer such as polyester, a radiopaque metal such as platinum, or a combination thereof, including, but not limited to, known polymeric fiber or filament materials or polymeric fiber or filament composites. Moreover, reinforcing filaments 204 and 206 can each be a monofilament, braided rope or wire, or a wire or cable.
[0071] The length of implant 200 could be from about 5 mm to about 1500 mm, preferably from about 1 cm to about 50 cm, and the diameter or effective diameter could be from about 0.25 mm to about 12 mm, preferably from about 0.50 mm to about 0.5 mm. The foam sections are each from about 0.5 mm to about 1 cm in length. Each foam section 210 is carefully trimmed or shaved by hand to a desired diameter. The outer diameter of each foam section should be equal to or slightly less than the inner diameter of the corresponding introducer sheath, discussed below. The reinforcing filaments 204 and 206 can be inserted into implant 200 by hand or by mechanical means such as a mechanical stitching or sewing machine.
[0072] In an embodiment of the invention, one or more elongate structural members in the device, such as filaments, may be included and, if so, may be provided with features or coupled to one another to confer desired properties. Filament 204 may be polymeric fiber, carbon fiber, glass fiber, synthetic suture, a single platinum wire, other metallic fiber, a twist or braid of platinum wire and polymeric fiber or filament, or twisted or braided double platinum wires or other materials or combinations thereof. Filament 206 is polymeric fiber or other filament such as are described above. Filament 204 or filament 206 can also be a monofilament fiber, co- mingled fibers, knotted, twisted braided rope, wire, a cable, composite scaffold, mesh, woven mesh or knitted mesh, or other material, structure or combination. In one embodiment according to the invention, filament 204 can be a structural element. Filament 204 may comprise a subassembly prepared using a coil winder and separate spools of fibers used to make polymeric fibers or filaments and platinum wires of differing thicknesses, thereby creating a twisted rope-like composite subassembly with varying stiffness and radiopacity. Known methods such as braiding may also be used to create such a subassembly. In another embodiment of the invention, the components of filament 204 may be available on separate spools or spindles and the final structural element can be formed during the attachment or the incorporation of the matrix member 202 to filament 204. hi another embodiment, filament 204 may comprise a sub- assembly in which a platinum micro coil string wound from platinum micro wire, over a fiber core or over the platinum wire core, will provide more integrity for pull/push action including good radiopacity. Construction or fabrication of filament 204 can be achieved in, for example, by using a sewing machine. Instead of using twisted platinum wire with fiber into braid and than loaded into sawing machine, in one embodiment a regular coil having inner core fiber or platinum wire is then loaded into the sewing machine to get knotted with the second sewing machine polymeric fiber or filament or wire string.
[0073] The platinum wire useful according to the invention preferably has a diameter of from about 0.0005 in. to about 0.005 in., more preferably from about 0.001 in. to about 0.003 in. Suitable platinum wire is available from sources such as Sigmund Cohn Corp. The fibers useful according to the invention comprise commercially available, non-absorbable polymeric fibers used to make suture fiber or filament having an effective diameter of from about 0.0005 in. to about 0.010 in., preferably from about 0.010 in. to about 0.005 in. Preferably the fibers are available on spools and have compositions and diameters comparable to commercially available sutures, for example, sutures available from Johnson & Johnson under the name ETHIBOND EXCEL®, PROLENE®, ETHILON®, Coated VICRYL®, or MONOCRYL®. [0074] Varying the structural filaments results in implants according to the invention having different characteristics. When each of the filaments is polymeric fiber or filament, the resulting implant is "Ultra Soft", as set forth in the table below. When at least one of the filaments includes platinum wire, the resulting implant is "Soft" or "Stiff. The stiffness of the device can be measured by the slope of the load versus extension curves during an uniaxial tensile pull using a tensile testing machine and can be in the range of from 1 to 200 pounds per inch (0.18 N/mm to 35 N/mm), preferably in the range of from 5 to 100 pounds per inch (0.88 N/mm to 18 N/mm). The breaking strength of the device can be measured during an uniaxial tensile pull using a tensile testing machine and can be in the range of from approximately 0.05 to 23 pounds (0.2 to 100 Newtons) and preferably in the range of approximately 0.05 to 7 pounds (1.0 to 30 Newtons).
Table 1.
Figure imgf000023_0001
[0075] It is preferred to include additional platinum markers to be crimped in from 1 to 10 mm sequences to provide safe radiopacity/visibility. Framing coils or a stent may be used to prevent migration. Delivery of the Ultra Soft implant requires use of a delivery system with a longitudinally extending core-wire to support the implant, an example of which delivery system can be seen in co-pending, commonly assigned U.S. patent application Serial No. 11/229,044, filed September 15, 2005, incorporated herein by reference, especially Figure 16 and the supporting language therefore, or hydraulic injection with a syringe. Delivery of the Soft or Stiff implants requires a pusher member as described below in Figures 15, 16, and 17.
[0076] When according to the invention one structural filament is a platinum wire and the other structural filament is polymeric fiber or filament, the resulting implant behaves like a coil to form helical packing during deployment into the aneurysm sac. A significant difference between an implant of the invention and a coil is that the implant of the invention does not have a predetermined memory, as does a coil. Also, the implant of the invention is malleable and will conform to the dimensions of the aneurysm sac. The stiffness can be controlled by varying the diameter of the platinum wire or the structure, as shown above, and the filament structure can act as a framing structure in lieu of the framing coils or stent necessary with a softer implant. The stiffness can also be controlled by varying the number of platinum wires used. The stiffer implants function to prevent migration and to facilitate better packing of the aneurysm sac, while the softer versions can be used as filler material to optimally embolize the aneurysm. This stiffer implant may be more useful for different vessel occlusion applications within the body. Delivery of the stiffer implant can be accomplished with a regular delivery system not having a supporting core-wire mandrel or hydraulic injection.
[0077] It is within the scope of the invention that each filament can be a platinum wire. The resulting implant will be similar to the implant described above but slightly stiffer and more radiopaque. [0078] In an embodiment of the invention implant 200 has regularly spaced radiopaque markers that are attached to every second to every sixth knot, preferably every third or fourth knot. These radiopaque markers tend to encourage the chain-like behavior that is characteristic of this embodiment. Notching of the elastomeric matrix/structural assembly and optional periodic crimping of platinum marker bands will allow the implant of the invention to bend and fold when deployed in an aneurysm and break like a chain. This bending and folding allows the implant to conformally fill the aneurysm sac like a liquid when deployed from the microcatheter. The overall resultant phenomenon is again similar to that of spaghetti filling a bowl or a metallic chain folding onto itself. In certain cases the implant fills the aneurysm sac in a manner similar to that of very viscous liquid flow. When multiple implants are placed in an aneurysm, the implants or devices form shapes containing curvatures or those that fold onto themselves optionally can be compressed further as they make contact during delivery with themselves or with other delivered devices in the aneurysm or with wall of the aneurysm, thereby making it easier to pack in a superior fashion. Platinum marker bands will impart additional radiopacity.
[0079] In another embodiment of the invention radiopaque microstaples instead of the radiopaque markers could be regularly spaced along the length of the implant every second to every sixth knot. This configuration would also encourage chain-like behavior.
[0080] A packaging system 218 for the storage and/or introduction of an implant such as implant 200 or other implants according to the invention is shown in Figure 15. Proximal end 214 of implant 200 is engaged within an introducer sheath 220 by the distal end 222 of a pusher rod or member 224. The proximal end 226 of sheath 220 engages the distal portion 228 of a manifold or side arm 230, which has an opening 232 for continuous flush. Pusher member 224 extends proximally through valve 234, and pusher member 224 has a lumen (not shown) which receives an interlocking wire 238, which provides support to pusher member 224 and helps retain implant 200.
[0081] For delivery of implant 200 or another occlusion device according to the invention to a patient, a flushing solution such as saline solution is introduced into opening 232 of system 218 to remove air and straighten out implant 200. Then, the tapered distal tip 242 of sheath 220 is introduced with continuous flushing into the hemostastis valve 244 of a side arm 246 of a micro-catheter as'sembly 248 such as is shown in Figure 16. Sheath 220 is inserted into micro-catheter 250, after which sheath 220 and side arm 230 are withdrawn, leaving implant 200, pusher member 224, and interlocking wire 238.
[0082] Delivery of implant 200 is shown in Figures 16 and 17, where the distal end 216 of implant 200 is advanced through micro-catheter 250 and through an artery 252 to a position adjacent an aneurysm 254. Implant 200 is advanced further to fill aneurysm 254. When aneurysm 254 has been filled, as shown in Figure 17, the distal end 222 of pusher rod 224 is disengaged from implant 200 and withdrawn through micro-catheter 250.
[0083] A detail of the connection between the proximal end 214 of implant 200 and the distal end member 262 of pusher member 224 is shown in Figures 18 and 19. Distal end member 262 comprises a lateral opening 264 to receive loop 212 from implant 200 and threading 266. The distal end 268 of wire 238 has reciprocal threads 270 that engage threading 266. In the position shown in Figure 18, the distal end 268 of wire 238 is adjacent to the internal end surface 274 of distal end 262, to trap loop 212. When wire 238 is rotated to cause wire 238 to disengage from threading 266, loop 212 disengages from wire 238 and pusher member 224 and releases implant 200. Also, preferably distal end member 262 comprises radiopaque material such as platinum to assist an operator during delivery. For example, distal end member 262 could comprise a section of platinum hypotube. More preferably, the distal end 268 of wire 238 is also radiopaque, which assists the operator during the procedure. When distal end 268 and distal end 262 are engaged, there will be a single spot under fluoroscopy; however, when distal end 268 and distal end 262 disengage, and release the loop from the implant, there will then be two separate spots under fluoroscopy to signify that release.
[0084] Advancing through the micro-catheter 250 provides controlled delivery or retraction of implant 200 into the aneurysm cavity with the pusher member 224 until desired positioning of implant 200 is accomplished. Due to the nature of the implant material, the implant fills the aneurysm cavity like a liquid complying with the geometry of the cavity. Continuous flush or pump of hydraulically pressurized solution such as saline solution is applied via micro-catheter through the micro- catheter side arm at the proximal end to support or drive the advancement of the implant through the catheter lumen. Dependent upon the size of the aneurysm, single or multiple implants may be necessary to achieve total occlusion. The packing density, that is, the ratio of volume of embolic material to volume of the aneurysm sac, ranges from about 50 to about 200%. Implant 200 can be retracted, before it is detached, and repositioned for precise, controlled deployment and delivery.
[0085] Implant 200 is not self-supporting and has no predetermined shape. It conforms significantly better to the geometry of the aneurysm than other implants due to the formation of a light, non-traumatic "string-ball" casting the cavity like a liquid. Because of this important feature the implant material will provide permanent stability of the desired total occlusion. An additional important feature of implant 200 is that it provides excellent tissue ingrowth to seal the aneurysm cavity from the parental artery. There is superior tissue ingrowth due to the porous nature of the reticulated matrix enhanced by structural reticulation created by plication/folding within the aneurysm. Also, plication enhances conformal space filling that eliminates device compaction and recanalization. [0086] The implant 298 shown in Figures 2OA and 2OB comprises a flat, preferably square or rectangular, member 300 that can be rolled up to fit in a delivery catheter (not shown). Member 300 preferably has surgical sutures, optionally absorbable, or radiopaque wire 302 sewn around the outer edges 304 and also diagonally 306. As shown in Figure 2OB, implant 298 can be rolled up to fit within a lumen of a delivery catheter. Upon deployment implant 298 would unroll to fill an aneurysm sac. An advantage of this particular embodiment is the relatively large surface area that is available for occlusion. It is anticipated that implant 298 could be from about 0.25 mm to about 3 mm in thickness and from about 1 mm to about 50 mm in length on the lateral edges.
[0087] Figure 21 represents an implant 310 where a thin string structure 312 has been cut from a flat member 314. Structure 312 is similar to implant 182 but with or without the internal suture or wire member. Manufacturing implant 310 in this manner provided memory support without nitinol support.
[0088] Figures 22A and 22B represent structures that may have an unexpanded shape, for example, cylindrical shape 318, that expands to an expanded shape, for example, spherical shape 320, due to internal frames (not shown). The outer surface 322 of shape 320 could comprise coils or braids, for example, or different shapes can be sutured together using coils and/or patches to provide maximum surface area for occlusion.
[0089] Implant 324 shown in Figures 23 A and 23B is representative of a nitinol or other shape-memory wire member 326 having a foam cover 328. Implant 324 is compressed for delivery, as shown in Figure 23 A, and then expands to the configuration shown in Figure 23B upon deployment. [0090] A cylindrically-shaped implant 330 with slots 332 is shown in Figures
24 A and 24B. As can be appreciated in the radial cross-section of Figure 24B, implant 330 may have one or more radiopaque bend markers 334. An advantage of this shape is that the slots permit the implant to bend to maximize surface area during deployment.
[0091] Examples of such shapes include, but are not limited to, spheres, hollow spheres, cylinders, hollow cylinders, noodles, cubes, pyramids, tetrahedrons, hollow cylinders with lateral slots, trapezoids, parallelepipeds, ellipsoids, rods, tubes, or elongated prismatic forms, folded, coiled, helical or other more compact configurations, segmented cylinders where "sausage-like" segments have been formed, flat square or rectangular shapes, daisy shapes, braided shapes, or flat spiral shapes, optionally with surgical suture or radiopaque wire support extending therein.
[0092] Certain embodiments of the invention comprise porous, reticulated biodurable elastomeric implants, which are also compressible and exhibit resilience in their recovery, that have a diversity of applications and can be employed, by way of example, in management of vascular malformations, such as for aneurysm control, arteriovenous malfunction, arterial embolization or other vascular abnormalities, or as substrates for pharmaceutically-active agent, e.g., for drug delivery. Thus, as used herein, the term "vascular malformation" includes but is not limited to aneurysms, arteriovenous malfunctions, arterial embolizations and other vascular abnormalities. Other embodiments include reticulated, biodurable elastomeric implants for in vivo delivery via catheter, endoscope, arthroscope, laparoscope, cystoscope, syringe or other suitable delivery-device and can be satisfactorily implanted or otherwise exposed to living tissue and fluids for extended periods of time, for example, at least 29 days. [0093] There is a need in medicine, as recognized by the present invention, for atraumatic implantable devices that can be delivered to an in vivo patient site, for example a site in a human patient, that can occupy that site for extended periods of time without being harmful to the host. In one embodiment, such implantable devices can also eventually become biologically integrated, e.g., ingrown with tissue. Various implants have long been considered potentially useful for local in situ delivery of biologically active agents and more recently have been contemplated as useful for control of endovascular conditions including potentially life-threatening conditions such as cerebral and aortic abdominal aneurysms, arterio venous malfunction, arterial embolization or other vascular abnormalities.
[0094] It would be desirable to have an implantable system which, e.g., can optionally cause immediate thrombotic response leading to clot formation, and eventually lead to fibrosis, i.e., allow for and stimulate natural cellular ingrowth and proliferation into vascular malformations and the void space of implantable devices located in vascular malformations, to stabilize and possibly seal off such vascular abnormalities in a biologically sound, effective and lasting manner.
[0095] In one embodiment of the invention, cellular entities such as fibroblasts and tissues can invade and grow into a reticulated elastomeric matrix. In due course, such ingrowth can extend into the interior pores and interstices of the inserted reticulated elastomeric matrix. Eventually, the elastomeric matrix can become substantially filled with proliferating cellular ingrowth that provides a mass that can occupy the site or the void spaces in it. The types of tissue ingrowth possible include, but are not limited to, fibrous tissues and endothelial tissues.
[0096] In another embodiment of the invention, the implantable device or device system causes cellular ingrowth and proliferation throughout the site, throughout the site boundary, or through some of the exposed surfaces, thereby sealing the site. Over time, this induced fibrovascular entity resulting from tissue ingrowth can cause the implantable device to be incorporated into the aneurysm wall. Tissue ingrowth can lead to very effective resistance to migration of the implantable device over time. It may also prevent recanalization of the aneurysm. In another embodiment, the tissue ingrowth is scar tissue which can be long-lasting, innocuous and/or mechanically stable. In another embodiment, over the course of time, for example, for from 2 weeks to 3 months to 1 year, implanted reticulated elastomeric matrix becomes completely filled and/or encapsulated by tissue, fibrous tissue, scar tissue or the like.
[0097] The invention has been described herein with regard to its applicability to aneurysms, particularly cerebral aneurysms. It should be appreciated that the features of the implantable device, its functionality, and interaction with an aneurysm cavity, as indicated above, can be useful in treating a number of arteriovenous malformations ("AVM") or other vascular abnormalities. These include AVMs, anomalies of feeding and draining veins, arteriovenous fistulas, e.g., anomalies of large arteriovenous connections, abdominal aortic aneurysm endograft endoleaks (e.g., inferior mesenteric arteries and lumbar arteries associated with the development of Type II endoleaks in endograft patients).
[0098] Shaping and sizing can include custom shaping and sizing to match an implantable device to a specific treatment site in a specific patient, as determined by imaging or other techniques known to those in the art. In particular, one or at least two comprise an implantable device system for treating an undesired cavity, for example, a vascular malformation.
[0099] Some materials suitable for fabrication of the implants according to the invention will now be described. Implants useful in this invention or a suitable hydrophobic scaffold comprise a reticulated polymeric matrix formed of a biodurable polymer that is elastomeric and resiliently-compressible so as to regain its shape after being subjected to severe compression during delivery to a biological site such as vascular malformations described here. The structure, morphology and properties of the elastomeric matrices of this invention can be engineered or tailored over a wide range of performance by varying the starting materials and/or the processing conditions for different functional or therapeutic uses.
[00100] The inventive implantable device is reticulated, i.e., comprises an interconnected network of pores and channels and voids that provides fluid permeability throughout the implantable device and permits cellular and tissue ingrowth and proliferation into the interior of the implantable device. The inventive implantable device is reticulated, i.e., comprises an interconnected and/or intercommunicating network of pores and channels and voids that provides fluid permeability throughout the implantable device and permits cellular and tissue ingrowth and proliferation into the interior of the implantable device. The inventive implantable device is reticulated, i.e., comprises an interconnected and/or intercommunicating network of pores and/or voids and/or channels that provides fluid permeability throughout the implantable device and permits cellular and tissue ingrowth and proliferation into the interior of the implantable device. The biodurable elastomeric matrix or material is considered to be reticulated because its microstructure or the interior structure comprises inter-connected and intercommunicating pores and/or voids bounded by configuration of the struts and intersections that constitute the solid structure. The continuous interconnected void phase is the principle feature of a reticulated structure.
[00101] Preferred scaffold materials for the implants have a reticulated structure with sufficient and required liquid permeability and thus selected to permit blood, or other appropriate bodily fluid, and cells and tissues to access interior surfaces of the implants. This happens due to the presence of inter-connected and intercommunicating, reticulated open pores and/or voids and/or channels that form fluid passageways or fluid permeability providing fluid access all through. [00102] Preferred materials are at least partially hydrophobic reticulated, elastomeric polymeric matrix for fabricating implants according to the invention are flexible and resilient in recovery, so that the implants are also compressible materials enabling the implants to be compressed and, once the compressive force is released, to then recover to, or toward, substantially their original size and shape. For example, an implant can be compressed from a relaxed configuration or a size and shape to a compressed size and shape under ambient conditions, e.g., at 250C to fit into the introducer instrument for insertion into the vascular malformations (such as an aneurysm sac or endoloeak nexus within the sac). Alternatively, an implant may be supplied to the medical practitioner performing the implantation operation, in a compressed configuration, for example, contained in a package, preferably a sterile package. The resiliency of the elastomeric matrix that is used to fabricate the implant causes it to recover to a working size and configuration in situ, at the implantation site, after being released from its compressed state within the introducer instrument. The working size and shape or configuration can be substantially similar to original size and shape after the in situ recovery.
[00103] Preferred scaffolds are reticulated elastomeric polymeric materials having sufficient structural integrity and durability to endure the intended biological environment, for the intended period of implantation. For structure and durability, at least partially hydrophobic polymeric scaffold materials are preferred although other materials may be employed if they meet the requirements described herein. Useful materials are preferably elastomeric in that they can be compressed and can resiliently recover to substantially the pre-compression state. Alternative reticulated polymeric materials with interconnected pores or networks of pores that permit biological fluids to have ready access throughout the interior of an implant may be employed, for example, woven or uonwoven fabrics or networked composites of microstructural elements of various forms. [00104] A partially hydrophobic scaffold is preferably constructed of a material selected to be sufficiently biodurable, for the intended period of implantation that the implant will not lose its structural integrity during the implantation time in a biological environment. The biodurable elastomeric matrices forming the scaffold do not exhibit significant symptoms of breakdown, degradation, erosion or significant deterioration of mechanical properties relevant to their use when exposed to biological environments and/or bodily stresses for periods of time commensurate with the use of the implantable device. In one embodiment, the desired period of exposure is to be understood to be at least 29 days, preferably several weeks and most preferably 2 to 5 years or more. This measure is intended to avoid scaffold materials that may decompose or degrade into fragments, for example, fragments that could have undesirable effects such as causing an unwanted tissue response.
[00105] The void phase, preferably continuous and interconnected, of the reticulated polymeric matrix that is used to fabricate the implant of this invention may comprise as little as 50% by volume of the elastomeric matrix, referring to the volume provided by the interstitial spaces of elastomeric matrix before any optional interior pore surface coating or layering is applied. In one embodiment, the volume of void phase as just defined, is from about 70% to about 99% of the volume of elastomeric matrix. In another embodiment, the volume of void phase is from about 80% to about 98% of the volume of elastomeric matrix. In another embodiment, the volume of void phase is from about 90% to about 98% of the volume of elastomeric matrix.
[00106] As used herein, when a pore is spherical or substantially spherical, its largest transverse dimension is equivalent to the diameter of the pore. When a pore is non-spherical, for example, ellipsoidal or tetrahedral, its largest transverse dimension is equivalent to the greatest distance within the pore from one pore surface to another, e.g., the major axis length for an ellipsoidal pore or the length of the longest side for a tetrahedral pore. For those skilled in the art, one can routinely estimate the pore frequency from the average cell diameter in microns. [00107] In one embodiment relating to vascular malformation applications and the like, to encourage cellular ingrowth and proliferation and to provide adequate fluid permeability, the average diameter or other largest transverse dimension of pores is at least about 50 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 100 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 150 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 250 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than about 250 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than about 250 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 275 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than about 275 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than 275 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is at least about 300 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than about 300 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is greater than 300 μm. In one embodiment the reticulated biodurable elastomeric matrix can have a larger dimension of from about 1 to about 100 mm optionally from about 3 to 50 mm, when a plurality of relatively small implants is employed.
[00108] In another embodiment relating to vascular malformation applications and the like, the average diameter or other largest transverse dimension of pores is not greater than about 900 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 850 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 800 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 700 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 600 μm. In another embodiment, the average diameter or other largest transverse dimension of pores is not greater than about 500 μm.
[00109] In one embodiment, the reticulated polymeric matrix that is used to fabricate the implants of this invention has any suitable bulk density, also known as specific gravity, consistent with its other properties. For example, in one embodiment, the bulk density may be from about 0.005 to about 0.15 g/cc (from about 0.31 to about 9.4 lb/ft3), preferably from about 0.015 to about 0.115 g/cc (from about 0.93 to about 7.2 lb/ft3) and most preferably from about 0.024 to about 0.104 g/cc (from about 1.5 to about 6.5 lb/ft3).
[00110] The reticulated elastomeric matrix has sufficient tensile strength such that it can withstand normal manual or mechanical handling during its intended application and during post-processing steps that may be required or desired without teaiing, breaking, crumbling, fragmenting or otherwise disintegrating, shedding pieces or particles, or otherwise losing its structural integrity. The tensile strength of the starting material(s) should not be so high as to interfere with the fabrication or other processing of elastomeric matrix. Thus, for example, in one embodiment, the reticulated polymeric matrix that is used to fabricate the implants of this invention may have a tensile strength of from about 700 to about 52,500 kg/m2 (from about 1 to about 75 psi). In another embodiment, elastomeric matrix may have a tensile strength of from about 7000 to about 28,000 kg/m2 (from about 10 to about 40 psi). Sufficient ultimate tensile elongation is also desirable. For example, in another embodiment, reticulated elastomeric matrix has an ultimate tensile elongation of at least about 50% to at least about 500%. In yet another embodiment, reticulated elastomeric matrix has an ultimate tensile elongation of at least 75% to at least about 300%. [00111] One embodiment for use in the practice of the invention is a reticulated elastomeric implant which is sufficiently flexible and resilient, i.e., resiliently- compressible, to enable it to be initially compressed under ambient conditions, e.g., at 250C, from a relaxed configuration to a first, compact configuration for delivery via a delivery-device, e.g., catheter, endoscope, syringe, cystoscope, trocar or other suitable introducer instrument, for delivery in vitro and, thereafter, to expand to a second, working configuration in situ. Furthermore, in another embodiment, an elastomeric matrix has the herein described resilient-compressibility after being compressed about 5-95% of an original dimension (e.g., compressed about 19/20th - l/20th of an original dimension). In another embodiment, an elastomeric matrix has the herein described resilient-compressibility after being compressed about 10-90% of an original dimension (e.g., compressed about 9/1 Oth - 1/1 Oth of an original dimension). As used herein, elastomeric implant has "resilient-compressibility", i.e., is "resiliently- compressible", when the second, working configuration, in vitro, is at least about 50% of the size of the relaxed configuration in at least one dimension. In another embodiment, the resilient-compressibility of elastomeric implant is such that the second, working configuration, in vitro, is at least about 80% of the size of the relaxed configuration in at least one dimension. In another embodiment, the resilient- compressibility of elastomeric implant is such that the second, working configuration, in vitro, is at least about 90% of the size of the relaxed configuration in at least one dimension. In another embodiment, the resilient-compressibility of elastomeric implant is such that the second, working configuration, in vitro, is at least about 97% of the size of the relaxed configuration in at least one dimension.
[00112] In another embodiment, an elastomeric matrix has the herein described resilient-compressibility after being compressed about 5-95% of its original volume (e.g., compressed about 19/20th - l/20th of its original volume). In another embodiment, an elastomeric matrix has the herein described resilient-compressibility after being compressed about 10-90% of its original volume (e.g., compressed about 9/1 Oth - 1/1 Oth of its original volume). As used herein, "volume" is the volume swept-out by the outermost three-dimensional contour of the elastomeric matrix. In another embodiment, the resilient-compressibility of elastomeric implant is such that the second, working configuration, in vivo, is at least about 50% of the volume occupied by the relaxed configuration. In another embodiment, the resilient- compressibility of elastomeric implant is such that the second, working configuration, in vivo, is at least about 80% of the volume occupied by the relaxed configuration. In another embodiment, the resilient-compressibility of elastomeric implant is such that the second, working configuration, in vivo, is at least about 90% of the volume occupied by the relaxed configuration. In another embodiment, the resilient- compressibility of elastomeric implant is such that the second, working configuration, in vivo, occupies at least about 97% of the of volume occupied by the elastomeric matrix in its relaxed configuration.
[00113] Without being bound by any particular theory, it is believed that the absence or substantial absence of cell walls in reticulated implants when compressed to very high degree will allow them to demonstrate resilient recovery in shorter time (such as recovery time of under 15 seconds when compressed to 75% of their relaxed configuration for 10 minutes and recovery time of under 35 seconds when compressed to 90% of their relaxed configuration for 10 minutes) as compared to un-reticulated porous foams.
[00114] In one embodiment, reticulated elastomeric matrix that is used to fabricate the implants of this invention has a compressive strength of from about 700 to about 70,000 kg/m2 (from about 1 to about 100 psi) at 50% compression strain. In another embodiment, reticulated elastomeric matrix has a compressive strength of from about 1,400 to about 105,000 kg/m2 (from about 2 to about 150 psi) at 75% compression strain. [00115] In another embodiment, reticulated elastomeric matrix that is used to fabricate the implants of this invention has a compression set, when compressed to 50% of its thickness at about 250C, of not more than about 30%. In another embodiment, elastomeric matrix has a compression set of not more than about 20%. In another embodiment, elastomeric matrix has a compression set of not more than about 10%. In another embodiment, elastomeric matrix has a compression set of not more than about 5%.
[00116] In another embodiment, reticulated elastomeric matrix that is used to fabricate the implants of this invention has a tear strength, of from about 0.18 to about 1.78 kg/linear cm (from about 1 to about 10 lbs/linear inch).
[00117] In another embodiment of the invention the reticulated elastomeric matrix that is used to fabricate the implant can be readily permeable to liquids, permitting flow of liquids, including blood, through the composite device of the invention. The water permeability of the reticulated elastomeric matrix is from about 50 l/min./psi/cm2 to about 500 l/min./psi/cm2, preferably from about 100 l/min./psi/cm2 to about 300 l/min./psi/cm2. In contrast, permeability of the unreticulated elastomeric matrix is below about 1 l/min./psi/cm2. In another embodiment, the permeability of the unretriculated elastomeric amtrix is below about 5 l/min./psi/cm2.
[00118] In general, suitable biodurable reticulated elastomeric partially hydrophobic polymeric matrix that is used to fabricate the implant of this invention or for use as scaffold material for the implant in the practice of the present invention, in one embodiment sufficiently well characterized, comprise elastomers that have or can be formulated with the desirable mechanical properties described in the present specification and have a chemistry favorable to biodurability such that they provide a reasonable expectation of adequate biodurability. [00119] Various biodurable reticulated hydrophobic polyurethane materials are suitable for this purpose. In one embodiment, structural materials for the inventive reticulated elastomers are synthetic polymers, especially, but not exclusively, elastomeric polymers that are resistant to biological degradation, for example, polycarbonate polyurethane-urea, polycarbonate polyurea-urethane, polycarbonate polyurethane, polycarbonate polysiloxane polyurethane, and polysiloxane polyurethane, and the like. Such elastomers are generally hydrophobic but, pursuant to the invention, may be treated to have surfaces that are less hydrophobic or somewhat hydrophilic. In another embodiment, such elastomers may be produced with surfaces that are less hydrophobic or somewhat hydrophilic.
[00120] The invention can employ, for implanting, a biodurable reticulatable elastomeric partially hydrophobic polymeric scaffold material or matrix for fabricating the implant or a material. More particularly, in one embodiment, the invention provides a biodurable elastomeric polyurethane scaffold material or matrix which is made by synthesizing the scaffold material or matrix preferably from a polycarbonate polyol component and an isocyanate component by polymerization, cross-linking and foaming, thereby forming pores, followed by reticulation of the porous material to provide a biodurable reticulated elastomeric product with interconnected and/or inter-communicating pores and channels. The product is designated as a polycarbonate polyurethane, being a polymer comprising urethane groups formed from, e.g., the hydroxyl groups of the polycarbonate polyol component and the isocyanate groups of the isocyanate component. In another embodiment, the invention provides a biodurable elastomeric polyurethane scaffold material or matrix which is made by synthesizing the scaffold material or matrix preferably from a polycarbonate polyol component and an isocyanate component by polymerization, cross-linking and foaming, thereby forming pores, and using water as a blowing agent and/or foaming agent during the synthesis, followed by reticulation of the porous material to provide a biodurable reticulated elastomeric product with inter-connected and/or inter-communicating pores and channels. This product is designated as a polycarbonate polyurethane-urea or polycarbonate polyurea-urethane, being a polymer comprising urethane groups formed from, e.g., the hydroxy! groups of the polycarbonate polyol component and the isocyanate groups of the isocyanate component and also comprising urea groups formed from reaction of water with the isocyanate groups. In all of these embodiments, the process employs controlled chemistry to provide a reticulated elastomeric matrix or product with good biodurability characteristics. The matrix or product employing chemistry that avoids biologically undesirable or nocuous constituents therein.
[00121] In one embodiment, the starting material for synthesizing the biodurable reticulated elastomeric partially hydrophobic polymeric matrix contains at least one polyol component to provide the so-called soft segement. For the purposes of this application, the term "polyol component" includes molecules comprising, on the average, about 2 hydroxyl groups per molecule, i.e., a difunctional polyol or a diol, as well as those molecules comprising, on the average, greater than about 2 hydroxyl groups per molecule, i.e., a polyol or a multi-functional polyol. In one embodiment, this soft segment polyol is terminated with hydroxyl groups, either primary or secondary. Exemplary polyols can comprise, on the average, from about 2 to about 5 hydroxyl groups per molecule. In one embodiment, as one starting material, the process employs a difunctional polyol comp'onent in which the hydroxyl group functionality of the diol is about 2. In another embodiment, the soft segment is composed of a polyol component that is generally of a relatively low molecular weight, typically from about 500 to about 6,000 daltons and preferably between 1000 to 2500 daltons. Examples of suitable polyol components include but not limited to polycarbonate polyol, hydrocarbon polyol, polysiloxane polyol, poly(carbonate-co- hydrocarbon) polyol, poly(carbonate-co-siloxane) polyol, poly(hydrocarbon-co- siloxane) polyol, polysiloxane polyol and copolymers and mixtures thereof. [00122] In one embodiment, the starting material for synthesizing the biodurable reticulated elastomeric partially hydrophobic polymeric matrix contains at least one isocyanate component and, optionally, at least one chain extender component to provide the so-called "hard segment". In one embodiment, the starting material for synthesizing the biodurable reticulated elastomeric partially hydrophobic polymeric matrix contains at least one isocyanate component. For the purposes of this application, the term "isocyanate component" includes molecules comprising, on the average, about 2 isocyanate groups per molecule as well as those molecules comprising, on the average, greater than about 2 isocyanate groups per molecule. The isocyanate groups of the isocyanate component are reactive with reactive hydrogen groups of the other ingredients, e.g., with hydrogen bonded to oxygen in hydroxyl groups and with hydrogen bonded to nitrogen in amine groups of the polyol component, chain extender, crosslinker and/or water. In one embodiment, the average number of isocyanate groups per molecule in the isocyanate component is about 2. In another embodiment, the average number of isocyanate groups per molecule in the isocyanate component is greater than about 2 is greater than 2.
[00123] In one embodiment, a small quantity of an optional ingredient, such as a multi-functional hydroxyl compound or other cross-linker having a functionality greater than 2, is present to allow crosslinking and / or to achieve a stable foam, i.e., a foam that does not collapse to become non-foamlike. Alternatively, or in addition, polyfunctional adducts of aliphatic and cycloaliphatic isocyanates can be used to impart cross-linking in combination with aromatic diisocyanates. Alternatively, or in addition, polyfunctional adducts of aliphatic and cycloaliphatic isocyanates can be used to impart cross-linking in combination with aliphatic diisocyanates. The presence of these components and adducts with functionality higher than 2 in the hard segment component allows for cross-linking to occur. [00124] Exemplary diisocyanates include aliphatic diisocyanates, isocyanates comprising aromatic groups, the so-called "aromatic diisocyanates", and mixtures thereof. Aliphatic diisocyanates include tetramethylene diisocyanate, cyclohexane- 1,2-diisocyanate, cyclohexane-l,4-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, methylene-bis-(p-cyclohexyl isocyanate) ("H 12 MDI"), and mixtures thereof. Aromatic diisocyanates include p-phenylene diisocyanate, 4,4'- diphenylmethane diisocyanate ("4,4'-MDI"), 2,4'-diphenylmethane diisocyanate ("2,4'-MDI"), polymeric MDI, and mixtures thereof. Examples of optional chain extenders include diols, diamines, alkanol amines or a mixture thereof.
[00125] In one embodiment, the starting material for synthesizing the biodurable reticulated elastomeric partially hydrophobic polymeric matrix contains at least one blowing agent such as water. Other exemplary blowing agents include the physical blowing agents, e.g., volatile organic chemicals such as hydrocarbons, ethanol and acetone, and various fluorocarbons, hydrofluorocarbons, chlorofluorocarbons, and hydrochlorofluorocarbons. In one embodiment, the hard segments also contain a urea component formed during foaming reaction with water. In one embodiment, the reaction of water with an isocyanate group yields carbon dioxide, which serves as a blowing agent. The amount of blowing agent, e.g., water, is adjusted to obtain different densities of non-reticulated foams. A reduced amount of blowing agent such as water may reduce the number of urea linkages in the material.
[00126] In one embodiment, implantable device can be rendered radiopaque to facilitate in vivo imaging, for example, by adhering to, covalently bonding to and/or incorporating into the elastomeric matrix itself particles of a radio-opaque material. Radio-opaque materials include titanium, tantalum, tungsten, barium sulfate or other suitable material known to those skilled in the art. [00127] In one embodiment, the starting material of -the biodurable reticulated elastomeric partially hydrophobic polymeric matrix is a commercial polyurethane polymers are linear, not crosslinked, polymers, therefore, they are soluble, can be melted, readily analyzable and readily characterizable. In this embodiment, the starting polymer provides good biodurability characteristics. The reticulated elastomeric matrix is produced by taking a solution of the commercial polymer such as polyurethane and charging it into a mold that has been fabricated with surfaces defining a microstructural configuration for the final implant or scaffold, solidifying the polymeric material and removing the sacrificial mold by melting, dissolving or subliming-away the sacrificial mold. The matrix or product employing a foaming process that avoids biologically undesirable or nocuous constituents therein.
[00128] Of particular interest are thermoplastic elastomers such as polyurethanes whose chemistry is associated with good biodurability properties, for example. In one embodiment, such thermoplastic polyurethane elastomers include polycarbonate polyurethanes, polysiloxane polyurethanes, polyurethanes with so-called "mixed" soft segments, and mixtures thereof. Mixed soft segment polyurethanes are known to those skilled in the art and include, e.g., polycarbonate-polysiloxane polyurethanes. In another embodiment, the thermoplastic polyurethane elastomer comprises at least one diisocyanate in the isocyanate component, at least one chain extender and at least one diol, and may be formed from any combination of the diisocyanates, difunctional chain extenders and diols described in detail above. Some suitable thermoplastic polyurethanes for practicing the invention, in one embodiment suitably characterized as described herein, include: polyurethanes with mixed soft segments comprising polysiloxane together with a polycarbonate component.
[00129] In one embodiment, the weight average molecular weight of the thermoplastic elastomer is from about 30,000 to about 500,000 Daltons. In another embodiment, the weight average molecular weight of the thermoplastic elastomer is from about 50,000 to about 250,000 Daltons. [00130] Some commercially-available thermoplastic elastomers suitable for use in practicing the present invention include the line of polycarbonate polyurethanes supplied under the trademark BIONATE® by The Polymer Technology Group Inc. (Berkeley, CA). For example, the very well-characterized grades of polycarbonate polyurethane polymer BIONATE® 80A, 55 and 90 are soluble in THF, DMF, DMAT, DMSO, or a mixture of two or more thereof, processable, reportedly have good mechanical properties, lack cytotoxicity, lack mutagenicity, lack carcinogenicity and are non-hemolytic. Another commercially-available elastomer suitable for use in practicing the present invention is the CHRONOFLEX® C line of biodurable medical grade polycarbonate aromatic polyurethane thermoplastic elastomers available from CardioTech International, Inc. (Woburn, MA).
[00131] Other possible embodiments of the materials used to fabricate the implants of this invention are described in co-pending, commonly assigned U.S. patent applications Serial No. 10/749,742, filed December 30, 2003, titled "Reticulated Elastomeric Matrices, Their Manufacture and Use in Implantable Devices", Serial No. 10/848,624, filed May 17, 2004, titled "Reticulated Elastomeric Matrices, Their Manufacture and Use In Implantable Devices", and Serial No. 10/990,982, filed July 27, 2004, titled "Endovascular Treatment Devices and Methods", each of which is incorporated herein by reference in its entirely.
[00132] If desired, the reticulated elastomeric implants or implants for packing the aneurysm sac or for other vascular occlusion can be rendered radiopaque to allow for visualization of the implants in situ by the clinician during and after the procedure, employing radioimaging. Any suitable radiopaque agent that can be covalently bound, adhered or otherwise attached to the reticulated polymeric implants may be employed including without limitation, tantalum and barium sulfate. In addition to incorporating radiopaque agents such as tantalum into the implant material itself, a further embodiment of the invention encompasses the use of radiopaque metallic components to impart radiopacity to the implant. For example, thin filaments comprised of metals with shape memory properties such as platinum or nitinol can be embedded into the implant and may be in the form of a straight or curved wire, helical or coil-like structure, umbrella structure, or other structure generally known to those skilled in the art. Alternatively, a metallic frame around the implant may also be used to impart radiopacity. The metallic frame may be in the form of a tubular structure similar to a stent, a helical or coil-like structure, an umbrella structure, or other structure generally known to those skilled in the art. Attachment of radiopaque metallic components to the implant can be accomplished by means including but not limited to chemical bonding or adhesion, suturing, pressure fitting, compression fitting, and other physical methods.
[00133] Some optional embodiments of the invention comprise apparatus or devices and treatment methods employing biodurable reticulated elastomeric implants 36 into which biologically active agents are incorporated for the matrix to be used for controlled release of pharmaceutically-active agents, such as a drug, and for other medical applications. Any suitable agents may be employed as will be apparent to those skilled in the art, including, for example, but without limitation thrombogenic agents, e.g., thrombin, anti-inflammatory agents, and other therapeutic agents that may be used for the treatment of abdominal aortic aneurysms. The invention includes embodiments wherein the reticulated elastomeric material of the implants is employed as a drug delivery platform for localized administration of biologically active agents into the aneurysm sac. Such materials may optionally be secured to the interior surfaces of elastomeric matrix directly or through a coating. In one embodiment of the invention the controllable characteristics of the implants are selected to promote a constant rate of drug release during the intended period of implantation.
[00134] The implants with reticulated structure with sufficient and required liquid permeability and permit blood, or other appropriate bodily fluid, to access interior surfaces of the implants, which optionally are drug-bearing. This happens due to the presence of inter-connected, reticulated open pores that form fluid passageways or fluid permeability providing fluid access all through and to the interior of the matrix for elution of pharmaceutically-active agents, e.g., a drug, or other biologically useful materials.
[00135] In a further embodiment of the invention, the pores of biodurable reticulated elastomeric matrix that are used to fabricate the implants of this invention are coated or filled with a cellular ingrowth promoter. In another embodiment, the promoter can be foamed. In another embodiment, the promoter can be present as a film. The promoter can be a biodegradable material to promote cellular invasion of pores biodurable reticulated elastomeric matrix that are used to fabricate the implants of this invention in vivo. Promoters include naturally occurring materials that can be enzymatically degraded in the human body or are hydrolytically unstable in the human body, such as fibrin, fibrinogen, collagen, elastin, hyaluronic acid and absorbable biocompatible polysaccharides, such as chitosan, starch, fatty acids (and esters thereof), glucoso-glycans and hyaluronic acid. In some embodiments, the pore surface of the biodurable reticulated elastomeric matrix that are used to fabricate the implants of this invention is coated or impregnated, as described in the previous section but substituting the promoter for the biocompatible polymer or adding the promoter to the biocompatible polymer, to encourage cellular ingrowth and proliferation.
[00136] One possible material for use in the present invention comprises a resiliency compressible composite polyurethane material comprising a hydrophilic foam coated on and throughout the pore surfaces of a hydrophobic foam scaffold. One suitable such material is the composite foam disclosed in co-pending, commonly assigned U.S. patent applications Serial No. 10/692,055, filed October 22, 2003, Serial No. 10/749,742, filed December 30, 2003, Serial No. 10/848,624, filed May 17, 2004, and Serial No. 10/900,982, filed July 27, 2004, each of which is incorporated herein by reference in its entirety. The hydrophobic foam provides support and resilient compressibility enabling the desired collapsing of the implant for delivery and reconstitution in situ.
[00137] The reticulated biodurable elastomeric and at least partially hydrophilic material_can be used to carry a variety of therapeutically useful agents, for example, agents that can aid in the healing of the aneurysm, such as elastin, collagen or other growth factors that will foster fibroblast proliferation and ingrowth into the aneurysm, agents to render the foam implant non-thrombogenic, or inflammatory chemicals to foster scarring of the aneurysm. Furthermore the hydrophilic foam, or other agent immobilizing means, can be used to carry genetic therapies, e.g. for replacement of missing enzymes, to treat atherosclerotic plaques at a local level, and to release agents such as antioxidants to help combat known risk factors of aneurysm.
[00138] Pursuant to the present invention it is contemplated that the pore surfaces may employ other means besides a hydrophilic foam to secure desired treatment agents to the hydrophobic foam scaffold.
[00139] The agents contained within the implant can provide an inflammatory response within the aneurysm, causing the walls of the aneurysm to scar and thicken. This can be accomplished using any suitable inflammation inducing chemicals, such as sclerosants like sodium tetradecyl sulphate (STS), polyiodinated iodine, hypertonic saline or other hypertonic salt solution. Additionally, the implant can contain factors that will induce fibroblast proliferation, such as growth factors, tumor necrosis factor and cytokines.
EXAMPLES
Example 1: Fabrication OfA Crosslinked Reticulated Polyurethane Matrix
The aromatic isocyanate RUBINATE 9258 (from Huntsman) was used as the isocyanate component. RUBlNATE 9258, which is a liquid at 25°C, contains 4,4'-MDI and 2,4'-MDI and has an isocyanate functionality of about 2.33. A diol, poly(l,6-hexanecarbonate)diol (POLY-CD CD220 from Arch Chemicals) with a molecular weight of about 2,000 Daltons was used as the polyol component and was a solid at 250C. Distilled water was used as the blowing agent. The blowing catalyst used was the tertiary amine triethylenediamine (33% in dipropylene glycol; DABCO 33LV from Air Products). A silicone-based surfactant was used (TEGOSTAB® BF 2370 from Goldschmidt). A cell-opener was used (ORTEGOL® 501 from Goldschmidt). The viscosity modifier propylene carbonate (from Sigma-Aldrich) was present to reduce the viscosity. The proportions of the components that were used are set forth in the following table:
Table 2.
Figure imgf000049_0001
The polyol component was liquefied at 7O0C in a circulating-air oven, and 100 g thereof was weighed out into a polyethylene cup. 5.8 g of viscosity modifier was added to the polyol component to reduce the viscosity, and the ingredients were mixed at 3100 rpm for 15 seconds with the mixing shaft of a drill mixer to form "Mix-1". 0.66 g of surfactant was added to Mix-1, and the ingredients were mixed as described above for 15 seconds to form "Mix-2". Thereafter, 1.00 g of cell opener was added to Mix-2, and the ingredients were mixed as described above for 15 seconds to form "Mix-3". 47.25 g of isocyanate component were added to Mix-3, and the ingredients were mixed for 60 ± 10 seconds to form "System A".
2.38 g of distilled water was mixed with 0.53 g of blowing catalyst in a small plastic cup for 60 seconds with a glass rod to form "System B".
System B was poured into System A as quickly as possible while avoiding spillage. The ingredients were mixed vigorously with the drill mixer as described above for 10 seconds and then poured into a 22.9 cm x 20.3 cm x 12.7 cm (9 in. x 8 in. x 5 in.) cardboard box with its inside surfaces covered by aluminum foil. The foaming profile was as follows: 10 seconds mixing time, 17 seconds cream time, and 85 seconds rise time.
Two minutes after the beginning of foaming, i.e., the time when Systems A and B were combined, the foam was placed into a circulating-air oven maintained at 100- 1050C for curing for from about 55 to about 60 minutes. Then, the foam was removed from the oven and cooled for 15 minutes at about 25°C. The skin was removed from each side using a band saw. Thereafter, hand pressure was applied to each side of the foam to open the cell windows. The foam was replaced into the circulating-air oven and postcured at 100-1050C for an additional four hours. The average pore diameter of the foam, as determined from optical microscopy observations, was greater than about 275 μm.
The following foam testing was carried out according to ASTM D3574: Bulk density was measured using specimens of dimensions 50 mm x 50 mm x 25 mm. The density was calculated by dividing the weight of the sample by the volume of the specimen. A density value of 2.81 lbs/ft3 (0.0450 g/cc) was obtained.
Tensile tests were conducted on samples that were cut either parallel to or perpendicular to the direction of foam rise. The dog-bone shaped tensile specimens were cut from blocks of foam. Each test specimen measured about 12.5 mm thick, about 25.4 mm wide, and about 140 mm long; the gage length of each specimen was 35 mm and the gage width of each specimen was 6.5 mm. Tensile properties (tensile strength and elongation at break) were measured using an INSTRON Universal Testing Instrument Model 1122 with a cross-head speed of 500 mm/mm (19.6 inches/minute). The average tensile strength perpendicular to the direction of foam rise was determined as 29.3 psi (20,630 kg/m2). The elongation to break perpendicular to the direction of foam rise was determined to be 266%.
The measurement of the liquid flow through the material is measured in the following way using a liquid permeability apparatus or Liquid Permeaeter (Porous Materials, Inc., Ithaca, NY). The foam sample was 8.5 mm in thickness and covered a hole 6.6 mm in diameter in the center of a metal plate that was placed at the bottom of the Liquid Permeaeter filled with water. Thereafter, the air pressure above the sample was increased slowly to extrude the liquid from the sample and the permeability of water through the foam was determined to be 0.11 L/min/psi/cm2. Example 2: Reticulation of a Crosslinked Polyurethane Foam
Reticulation of the foam described in Example 1 was carried out by the following procedure: A block of foam measuring approximately 15.25 cm x 15.25 cm x 7.6 cm (6 in. x 6 in. x 3 in.) was placed into a pressure chamber, the doors of the chamber were closed, and an airtight seal to the surrounding atmosphere was maintained. The pressure within the chamber was reduced to below about 100 millitorr by evacuation for at least about two minutes to remove substantially all of the air in the foam. A mixture of hydrogen and oxygen gas, present at a ratio sufficient to support combustion, was charged into the chamber over a period of at least about three minutes. The gas in the chamber was then ignited by a spark plug. The ignition exploded the gas mixture within the foam. The explosion was believed to have at least partially removed many of the cell walls between adjoining pores, thereby forming a reticulated elastomeric matrix structure.
The average pore diameter of the reticulated elastomeric matrix, as determined from optical microscopy observations, was greater than about 275 μm. A scanning electron micrograph image of the reticulated elastomeric matrix of this example (not shown here) demonstrated, e.g., the communication and interconnectivity of pores therein.
The density of the reticulated foam was determined as described above in Example 1. A post-reticulation density value of 2.83 lbs/ft3 (0.0453 g/cc) was obtained.
Tensile tests were conducted on reticulated foam samples as described above in Example 1. The average post-reticulation tensile strength perpendicular to the direction of foam rise was determined as about 26.4 psi (18,560 kg/m2). The post- reticulation elongation to break perpendicular to the direction of foam rise was determined to be about 250%. The average post-reticulation tensile strength parallel to the direction of foam rise was determined as about 43.3 psi (30,470 kg/m2). The post-reticulation elongation to break parallel to the direction of foam rise was determined to be about 270%.
Compressive tests were conducted using specimens measuring 50 mm x 50 mm x 25 mm. The tests were conducted using an INSTRON Universal Testing Instrument Model 1122 with a cross-head speed of 10 mm/min (0.4 inches /minute). The post- reticulation compressive strengths at 50% compression, parallel to and perpendicular to the direction of foam rise, were determined to be 1.53 psi (1,080 kg/m2) and 0.95 psi (669 kg/m2), respectively. The post-reticulation compressive strengths at 75% compression, parallel to and perpendicular to the direction of foam rise, were determined to be 3.53 psi (2,485 kg/m2) and 2.02 psi (1,420 kg/m2), respectively. The post-reticulation compression set, determined after subjecting the reticulated sample to 50% compression for 22 hours at 250C then releasing the compressive stress, parallel to the direction of foam rise, was determined to be about 4.5%.
The resilient recovery of the reticulated foam was measured by subjecting 1 inch (25.4 mm) diameter and 0.75 inch (19 mm) long foam cylinders to 75% uniaxial compression in their length direction for 10 or 30 minutes and measuring the time required for recovery to 90% ("t-90%") and 95% ("t-95%") of their initial length. The percentage recovery of the initial length after 10 minutes ("r-10") was also determined. Separate samples were cut and tested with their length direction parallel to and perpendicular to the foam rise direction. The results obtained from an average of two tests are shown in the following table:
Table 3.
Figure imgf000054_0001
In contrast, a comparable foam with little to no reticulation typically has t-90 values of greater than about 60-90 seconds after 10 minutes of compression.
The measurement of the liquid flow through the material is measured in the following way using a Liquid permeability apparatus or Liquid Permeaeter (Porous Materials, Inc., Ithaca, NY). The foam samples were between 7.0 and 7.7 mm in thickness and covered a hole 8.2 mm in diameter in the center of a metal plate that was placed at the bottom of the Liquid Permeaeter filled with water. The water was allowed to extrude through the sample under gravity and the permeability of water through the foam was determined to be 180 L/min/psi/cm2 in the direction of foam rise and 160 L/min/psi/cm in the perpendicular to foam rise.
Example 3: Histological Evaluation of a Plurality of Crosslinked Reticulated Polyurethane Matrix Implants in a Canine Carotid Bifurcation Aneurysm Model
An established animal model of cerebral aneurysms was used to evaluate the histologic outcomes of implanting a plurality of cylindrical implants machined from a block of cross-linked reticulated polyurethane matrix as described in Example 2. The three animals were sacrificed at the three-month timepoint to assess tissue response to the cross-linked reticulated polyurethane matrix. One of two different implant configurations was used in this experiment. The first configuration was a cylindrical implant measuring 6 mm diameter x 15 mm length. The second configuration was a segmented, cylindrical implant measuring 3 mm diameter x 15 mm length. To machine the implants, a rotating die cutter was used to cut 3 mm and 6 mm diameter cylinders. The implants were then trimmed to 15 mm in length. Implant dimensions were tested for acceptability by use of calipers and visualization under a stereo-microscope, with acceptance of implants measuring +/- 5% of target dimensions.
An aneurysm was surgically created at the carotid arterial bifurcation of three dogs. This model simulates the hemodynamics of a human saccular aneurysm, which typically occurs at an arterial bifurcation. After one month, a second embolization procedure was performed in which a plurality of implants machined from a block of cross-linked reticulated polyurethane matrix was delivered into the aneurysm sac using a guide catheter. The 6x15 mm cylindrical implants were delivered using a commercially available 7 Fr Cordis Vista-Brite guide catheter. The 3x15 mm cylindrical implants were delivered using a commercially available 5 Fr Cordis Vista- Brite guide catheter. A loader apparatus was used to pull compress the implants from their expanded state into a compressed state for introduction through the hemostasis valve of the guide catheter. An obturator was then used to push the compressed implant from the proximal end of the guide catheter to the distal end, where the implant was deployed in a slow, controlled manner into the aneurysm sac.
A plurality of implants was used in each of the three dogs to achieve post- procedural angiographic occlusion as shown in Table 4 below. Platinum coil markers (0.003" diameter) embedded in the central lumen of the implants allowed the implants to be readily visualized under standard fluoroscopy, in order to verify implant deployment, placement, and positioning. Table 4.
Figure imgf000056_0001
At three months following the embolization procedure, the animals were sacrificed to assess tissue response to the cross-linked reticulated polyurethane matrix. For histology processing, samples were dehydrated in a graded series of ethanol and embedded in methylmethacrylate plastic. After polymerization, each aneurysm was bisected (sawn) longitudinally by the Exakt method and glued onto a holding block for sectioning using a rotary microtome at 5 - 6 microns. The sections were mounted on charged slides and stained with hematoxylin-eosin and Movat pentaclirome stains. All sections were examined by light microscopy for the presence inflammation, healing response, calcification and integrity of the wall at the neck interface and surrounding aneurysm.
Gross observation indicated that the aneurysm sac was fully packed with no open spaces. There was nearly complete pannus growth on the luminal surface at the proximal neck interface with focal, luminal invagination (pocket). Longitudinal section through the proximal neck of the aneurysm showed greater than 95% luminal occlusion of aneurysm sac by reticulated polyurethane matrix. The luminal surface at the proximal interface showed almost complete covering by fibrous tissue with overlying endothelialization as shown in Figure 25, which is 2OX magnification showing fibrocollagenous tissue surrounding implant material and extending to luminal surface at proximal neck interface. There was nearly complete healing of tissue ingrowth surrounding the implanted material characterized by the presence of fibrocollagenous tissue (light-green and yellow by Movat Pentachrome stain) as shown in Figure 26, which is a low power (4X) Movat stain of the apex of the aneurysm showing marked fibrocollagenous tissue ingrowth.. There was minimal, focal organizing granulation tissue surrounding material (predominantly at the center of the occluded aneurysm) with mild, chronic inflammation consisting of lymphocytes and some giant cells, consistent with the healing response. There was almost complete replacement of elastic lamellae by fibrocollagenous tissue. No calcification was observed.
The histological response to the reticulated polyurethane matrix in this experiment demonstrated that the material can serve as a scaffold to support extensive organic tissue ingrowth with minimal inflammation and thereby holds promise as a bioactive solution to the treatment of cerebral aneurysms.
Example 4: Angiographic Outcomes From Use of Reticulated Polyurethane
Neurostring Implants in a Canine Carotid Bifurcation Aneurysm Model
An established animal model of cerebral aneurysms was used to evaluate the angiographic outcomes of implanting a 0.030" Neurostring implants made from cross- linked reticulated polyurethane matrix as described in Example 2.
To create the Neurostring implants, thin sheets measuring 2.0 mm in depth were sliced from a block of reticulated polyurethane matrix. A sewing machine was then used to stitch surgical suture measuring 0.003" in diameter through the thin foam sheet to form a straight line. Individual strings were cut by using micro-scissors to trim around the suture line under a microscope until the final outer diameter of 0.030" (outside edge of the foam string) was achieved. Neurostring implant dimensions were tested for acceptability by delivering each individual string through a custom-made 3.5F (0.035" inner diameter) microcatheter. Platinum bands were hand-crimped every 1.0 cm along the length of each neurostring implants to impart radiopacity.
An aneurysm was surgically created at the carotid arterial bifurcation of three dogs. This model simulates the hemodynamics of a human saccular aneurysm, which typically occurs at an arterial bifurcation. After one month, a second embolization procedure was performed as follows. After preparing the access site using standard surgical technique, a 6F Boston Scientific Guide Catheter with Straight Tip was advanced to the aneurysm. A Boston Scientific Excelsior 3F Microcatheter was then advanced through the guide catheter into the aneurysm neck. One or two GDC- 18 framing coils were then deployed through the microcatheter to frame the aneurysm. After positioning and detaching the framing coil, the Excelsior microcatheter was withdrawn. A custom-made 3.5F (0.035" inner diameter) microcatheter was then advanced through the guide catheter into the aneurysm neck. The Neurostring implant, loader, and pusher wire were removed from their sterile packaging. The loaded Neurostring implant and microcatheter were flushed with sterile saline. The loader/Neurostring implant was then introduced into the hemostasis valve of the microcatheter. The Neurostring implant was subsequently delivered into the aneurysm by pushing the implant with the pusher wire while using hydraulic assistance through the 3.5F custom microcatheter. The Neurostring implant was positioned and detached into the aneurysm. The pusher wire was removed from the microcatheter and an angiogram was performed to confirm occlusion. Neurostring implants ranging from 10 - 18 cm in length were deployed as necessary until angiographic occlusion was confirmed.
Table 4 below shows the quantities and volumes of framing coils and Neurostring implants used in each of the three animals. All 22 Neurostring implants were successfully delivered using hydraulic assistance and controlled mechanical detachment. Post-procedure angiographic occlusion was achieved in all three animals, with minor neck remnants.
Table 5.
Figure imgf000059_0001
At two-week followup, an angiogram was performed to assess angiographic outcomes including device stability (compaction) and aneurysm recanalization. All three dogs showed stable or progressing occlusion with no device compaction and no evidence of aneurysm recanalization. The angiographic series from BMX-5 is shown in Figures 27A to 27B, where Figure 27A represents pre-embolization, Figure 27B reoresents ϋost embolization, and Fieure 27C renresents follow-uD. The angiographic outcomes at two-week followup demonstrated that Neurostring implants can be utilized for the embolization of cerebral aneurysms. This experiment showed the Neurostring device is consistently deliverable through a 3F microcatheter, and that the Neurostring implants are stable with no evidence of device compaction, no migration, and no aneurysm recanalization at the two-week followup timepoint.
Example 5: Effects of Packing Density on Angiographic Outcomes Using
Reticulated Polyurethane Implants in a Canine Carotid Bifurcation Aneurysm Model
An established animal model of cerebral aneurysms was used to evaluate the impact of different packing densities on angiographic outcomes for two different configurations of implants machined from a block of cross-linked reticulated polyurethane matrix as described in Example 2. The study evaluated the efficacy of different packing densities using (i) cylindrical implants (3mm x 15mm, 6mm x 15mm) machined as described in Example 3; and (ii) 0.030" Neurostring implants machined as described in Example 4. Packing density effectiveness was measured as angiographic occlusion and device stability (no compaction) at two-week followup.
Table 6 below shows that packing densities ranging from 40% - 350% result in angiographic occlusion at two-week followup with stable or progressing occlusion and no device compaction. The one exception, BMX-I, was noted to occur in a dog with an unusual, giant, unstable aneurysm that continued to expand even at the two-week angiographic followup timepoint.
Table 6.
Figure imgf000061_0001
This experiment demonstrated that various configurations of implants machined from reticulated polyurethane matrix can be utilized to embolize large aneurysms in a wide range of packing densities (40% — 350%) with efficacious angiographic outcomes at two-week followup. The one-month animal was sacrificed to assess tissue response to the cross- linked reticulated polyurethane matrix. Gross observation indicated that the aneurysm sac was fully packed with no open spaces. Histology analysis showed a mild inflammatory response with a high degree of tissue ingrowth. Infiltration by inflammatory cells and migrating fibroblasts was consistent with aneurysm healing. There was no evidence of unorganized blood clotting which is thought to lead to aneurysm recanalization. This experiment supported the efficacy of crosslinked reticulated polyurethane implants for the treatment of cerebral aneurysms.
While illustrative embodiments of the invention have been described, it is, of course, understood that various modifications of the invention will be obvious to those of ordinary skill in the art. Such modifications are within the spirit and scope of the invention which is limited and defined only by the appended claims.

Claims

WE CLAIM:
1. An occlusion device comprising a flexible, longitudinally extending elastomeric matrix member, wherein the device assumes a non-linear shape capable of conformally filling a targeted vascular site.
2. The device of Claim 1 comprising: a longitudinally extending compressible elastomeric matrix member; and one or more compression members arranged in the compressible elastomeric matrix member to define two or more sections.
3. The device of Claim 2, wherein the longitudinally extending compressible elastomeric member has a lumen extending longitudinally therethrough.
4. The device of Claim 3, wherein the lumen in the compressible elastomeric matrix member comprises a flexible mesh lining.
5. The device of Claim 4, wherein the mesh lining comprises a shape memory alloy or polymer.
6. The device of Claim 5, wherein the shape memory alloy is nitinol.
7. The device of Claim 2, wherein the compressible elastomeric member has a proximal end and a distal end, a proximal spring coil is attached to said proximal end, and a distal spring coil is attached to said distal end.
8. The device of Claim 7, wherein the longitudinally extending compressible elastomeric member has a lumen extending longitudinally therethrough, the lumen in the compressible elastomeric matrix member comprises a flexible mesh lining, and the mesh lining extends distally to form a jacket around the distal coil and extends proximally to form a jacket around the proximal coil.
9. The device of Claim 7, wherein the proximal and distal coils each comprise a lumen in communication with the elastomeric matrix member lumen and capable of receiving a wire.
10. The device of Claim 7, wherein the proximal coil has a retaining member.
11. The device of Claim 7, wherein the proximal coil, the distal coil, or both comprise a shape memory alloy or polymer.
12. The device of Claim 11 , wherein the shape memory alloy is nitinol.
13. The device of Claim 1, wherein the elastomeric matrix is a biodurable, reticulated elastomeric matrix.
14. The d;?vice of Claim 1, wherein the elastomeric matrix is a polycarbonate polyurethane-urea, polycarbonate polyurea-urethane, polycarbonate polyurethane, or polycarbonate polysiloxane polyurethane.
15. The device of Claim 1 , wherein the elastomeric matrix is resiliently recoverable.
16. The device of Claim 1 which is useful for occluding an aneurysm.
17. The device of Claim 16, wherein the aneurysm is a cerebral aneurysm.
18. The device of Claim 1 which is useful for occluding a vessel.
19. A system for occluding a vessel or aneurysm comprising: an occlusion device of Claim 1 having a lumen extending longitudinally therethrough; a delivery catheter having proximal and distal ends and surrounding the compressible elastomeric matrix member and compressing the compressible elastomeric matrix member therein; a pushing catheter slidably positioned in the proximal end of the delivery catheter and having a proximal end and a distal end; and a wire having a proximal end and a distal end and slidably positioned within the proximal end of the pushing catheter and extending through the lumen of the compressible elastomeric matrix member of the occlusion device, wherein the distal end of the pushing catheter has an opening, the occlusion device has a retaining member attached thereto, and the retaining member extends through said opening to engage the wire.
20. The system of Claim 19, wherein the distal end of each of the delivery catheter and the pushing catheter has a radiopaque marker.
21. The system of Claim 19, wherein the compressible elastomeric matrix member has a distal coil with a distal end to receive the distal end of the wire.
22. The system of Claim 19, wherein the compressible elastomeric matrix member has a proximal end and a distal end, a proximal coil is attached to said proximal end, a distal coil is attached to said distal end, the lumen extends through the proximal coil and the distal coil, the wire extends into the distal coil, and the proximal coil has the retaining member attached thereto.
23. An occlusion device comprising: a flexible cylindrical structure having a external compressible elastomeric matrix surface, and internal means to cause the flexible structure to expand in a radial direction to form a substantially spherical shape.
24. The device of Claim 23, wherein the compressible elastomeric matrix is porous.
25. The device of Claim 23, wherein the internal means comprises a coil or threaded structure that is capable of engaging an external member with reciprocal structure.
26. The device of Claim 23 which is useful for occluding an aneurysm.
27. The device of Claim 26, wherein the aneurysm is a cerebral aneurysm.
28. The device of Claim 23 which is useful for occluding a vessel.
29. A system for occluding a vessel or aneurysm, comprising
a delivery catheter having a longitudinally extending lumen and proximal and distal ends; an occlusion device of Claim 23 positioned adjacent to distal end of the delivery catheter; a longitudinal member extending through the lumen of the delivery catheter at the lumen of the occlusion device, said longitudinal member has a lumen extending therethrough and a distal section comprising structure that engages the interna! means of the occlusion device.
30. The system of Claim 29 which also comprises a guidewire that extends through the lumen of the longitudinal member.
31. The system of Claim 29, wherein the distal section of the longitudinal member comprises a cylindrical section that extends distal to the occlusion device.
32. The system of Claim 29, wherein the internal means of the occlusion device comprises coils that engage coils on the distal section of the longitudinal member to cause the occlusion device to assume a spherical shape.
33. An occlusion device which comprises a longitudinal compressible elastomeric matrix member having one or more radiopaque markers that define two or more sections of the reticulated elastomeric matrix member in the longitudinal direction, wherein a flexible suture or wire extends longitudinally through the reticulated elastomeric matrix member.
34. The device of Claim 33, wherein the compressible elastomeric matrix is a biodurable, reticulated elastomeric matrix.
35. The device of Claim 34, wherein the matrix is a polycarbonate polyurethane-urea, polycarbonate polyurea-urethane, polycarbonate polyurethane, or polycarbonate polysiloxane polyurethane.
36. An occlusion device which comprises a multitude of longitudinally extending compressible elastomeric matrix members that are intertwined and have one or more radiopaque markers that define sections of the device in the longitudinal direction.
37. The device of Claim 36, wherein the compressible elastomeric matrix is a biodurable, reticulated elastomeric matrix.
38. The device of Claim 37, wherein the matrix is a polycarbonate polyurethane-urea, polycarbonate polyurea-urethane, polycarbonate polyurethane, or polycarbonate polysiloxane polyurethane.
39. An occlusion device which comprises a square or rectangular essentially flat compressible elastomeric matrix member that has sutures and/or radiopaque markers extending along the edges thereof and/or diagonally.
40. The device of Claim 39, wherein the compressible elastomeric matrix is a biodurable, reticulated elastomeric matrix.
41. The device of Claim 40, wherein the matrix is a polycarbonate polyurethane-urea, polycarbonate polyurea-urethane, polycarbonate polyurethane, or polycarbonate polysiloxane polyurethane.
42. An occlusion device which comprises a wire structure covered by compressible elastomeric matrix wherein the wire structure comprises regularly spaced sections that are attached at a single point and the structure compresses to an essentially flat structure but expands to a regularly spaced structure when pressure is released.
43. The device of Claim 42, wherein the compressible elastomeric matrix is a biodurable, reticulated elastomeric matrix.
44. The device of Claim 43, wherein the matrix is a polycarbonate polyurethane-urea, polycarbonate polyurea-urethane, polycarbonate polyurethane,. or polycarbonate polysiloxane polyurethane.
45. An occlusion device which comprises a cylindrically shaped wire structure comprising compressible elastomeric matrix and having lateral slots.
46. The device of Claim 45, wherein the compressible elastomeric matrix is a biodurable, reticulated elastomeric matrix.
47. The device of Claim 46, wherein the matrix is a polycarbonate polyurethane-urea, polycarbonate polyurea-urethane, polycarbonate polyurethane, or polycarbonate polysiloxane polyurethane.
48. A method of occluding an aneurysm or vessel which comprises deploying or inserting a device of Claim 1, 23, 33, 36, 39, 42, or 45 into an aneurysm or vessel in a compressed state and allowing the device to expand.
49.. The device of Claim 1 which has at least one longitudinally extending reinforcing filament or fiber.
50. The device of Claim 49, wherein there are two reinforcing filaments or fibers.
51. The device of Claim 50, wherein the reinforcing filaments or fibers are knotted or looped together at various points to secure the elastomeric matrix.
52. The device of Claim 51, where the reinforcing filaments or fibers are knotted together by radiopaque bands.
53. The device of Claim 49, wherein at least one reinforcing filament or fiber is radiopaque.
54. The device of Claim 49 which is useful for occluding an aneurysm.
55. The device of Claim 54, wherein the aneurysm is a cerebral aneurysm.
56. The device of Claim 49 which is useful for occluding a vessel.
57. A packaging or introducer system comprising: an introducer sheath having a longitudinally extending lumen and proximal and distal ends; an occlusion device of Claim 1 positioned within said lumen, said occlusion device having a proximal end; a side arm attached to the proximal end of the introducer sheath and having a hemostasis valve and a flusher port; and a pusher member extending through the hemostasis valve into the introducer sheath and having a distal end removably engaged to the proximal end of the occlusion device.
58. The system of Claim 57, wherein an interlocking wire having a distal end extends longitudinally into the pusher member, the occlusion device has a loop at its proximal end, the distal end of the pusher member has an opening through which said loop extends, the distal end of the interlocking wire is releasably held within the distal end of the pusher member, and the distal end of the interlocking wire releasably engages said loop so that the distal end of the pusher member releasably engages the proximal end of the occlusion device.
59. The system of Claim 58, wherein the distal end of the interlocking wire and the distal end of the pusher member are both radiopaque.
60. A method for occluding a vessel or aneurysm comprising: introducing an introducer system of Claim 57 into a delivery catheter having a longitudinally extending lumen and proximal and distal ends with hydraulic assistance; withdrawing the introducer sheath and side arm, leaving the occlusion device positioned within the lumen of the delivery catheter; advancing the occlusion device using the pusher member and hydraulic assistance to position the occlusion device within a targeted vascular site; disengaging the pusher member from the occlusion device; and withdrawing the pusher member.
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008051279A1 (en) * 2006-03-24 2008-05-02 Biomerix Corp Self-expandable endovascular device for aneurysm occlusion
EP2904998A1 (en) * 2012-04-24 2015-08-12 Urogyn B.V. Occluding compound for a fallopian tube
WO2016118420A1 (en) * 2015-01-20 2016-07-28 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US10420563B2 (en) 2016-07-08 2019-09-24 Neurogami Medical, Inc. Delivery system insertable through body lumen
US10736730B2 (en) 2015-01-20 2020-08-11 Neurogami Medical, Inc. Vascular implant
US10857012B2 (en) 2015-01-20 2020-12-08 Neurogami Medical, Inc. Vascular implant
US10925611B2 (en) 2015-01-20 2021-02-23 Neurogami Medical, Inc. Packaging for surgical implant
US11484319B2 (en) 2015-01-20 2022-11-01 Neurogami Medical, Inc. Delivery system for micrograft for treating intracranial aneurysms
US11883246B2 (en) * 2012-11-21 2024-01-30 Trustees Of Boston University Tissue markers and uses thereof

Families Citing this family (132)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4937453B2 (en) * 1999-05-27 2012-05-23 ユーロ−セルティック エス. ア. Formulation for applying anti-infective and / or anti-inflammatory agent
CA2525792C (en) 2003-05-15 2015-10-13 Biomerix Corporation Reticulated elastomeric matrices, their manufacture and use in implantable devices
US20050085836A1 (en) * 2003-09-12 2005-04-21 Jean Raymond Methods and devices for endothelial denudation to prevent recanalization after embolization
US7763077B2 (en) 2003-12-24 2010-07-27 Biomerix Corporation Repair of spinal annular defects and annulo-nucleoplasty regeneration
US20070190108A1 (en) * 2004-05-17 2007-08-16 Arindam Datta High performance reticulated elastomeric matrix preparation, properties, reinforcement, and use in surgical devices, tissue augmentation and/or tissue repair
EP2419048A4 (en) 2004-05-25 2014-04-09 Covidien Lp Vascular stenting for aneurysms
US8628564B2 (en) 2004-05-25 2014-01-14 Covidien Lp Methods and apparatus for luminal stenting
US20060206200A1 (en) 2004-05-25 2006-09-14 Chestnut Medical Technologies, Inc. Flexible vascular occluding device
US9675476B2 (en) 2004-05-25 2017-06-13 Covidien Lp Vascular stenting for aneurysms
US8267985B2 (en) 2005-05-25 2012-09-18 Tyco Healthcare Group Lp System and method for delivering and deploying an occluding device within a vessel
EP1750619B1 (en) 2004-05-25 2013-07-24 Covidien LP Flexible vascular occluding device
US8617234B2 (en) 2004-05-25 2013-12-31 Covidien Lp Flexible vascular occluding device
GB0419954D0 (en) 2004-09-08 2004-10-13 Advotek Medical Devices Ltd System for directing therapy
EP1793744B1 (en) 2004-09-22 2008-12-17 Dendron GmbH Medical implant
US7871578B2 (en) * 2005-05-02 2011-01-18 United Technologies Corporation Micro heat exchanger with thermally conductive porous network
CA2617172A1 (en) * 2005-08-26 2007-03-01 Tyco Healthcare Group Lp Absorbable surgical materials
WO2007100556A1 (en) 2006-02-22 2007-09-07 Ev3 Inc. Embolic protection systems having radiopaque filter mesh
US20130190676A1 (en) 2006-04-20 2013-07-25 Limflow Gmbh Devices and methods for fluid flow through body passages
US7594928B2 (en) 2006-05-17 2009-09-29 Boston Scientific Scimed, Inc. Bioabsorbable stents with reinforced filaments
BRPI0711784B8 (en) * 2006-06-15 2021-06-22 Microvention Inc embolization device constructed of expandable polymer and its method of preparation
US20080051759A1 (en) * 2006-08-24 2008-02-28 Boston Scientific Scimed, Inc. Polycarbonate polyurethane venous access devices
US8834515B2 (en) 2006-11-20 2014-09-16 Boston Scientific Scimed, Inc. Mechanically detachable vaso-occlusive device
US8926650B2 (en) 2006-11-20 2015-01-06 Boston Scientific Scimed, Inc. Mechanically detachable vaso-occlusive device
US8956381B2 (en) 2006-11-20 2015-02-17 Boston Scientific Scimed, Inc. Mechanically detachable vaso-occlusive device
US7850382B2 (en) 2007-01-18 2010-12-14 Sanford, L.P. Valve made from two materials and writing utensil with retractable tip incorporating same
US7488130B2 (en) 2007-02-01 2009-02-10 Sanford, L.P. Seal assembly for retractable instrument
KR20100015521A (en) 2007-03-13 2010-02-12 마이크로 테라퓨틱스 인코포레이티드 An implant, a mandrel, and a method of forming an implant
EP2460476B1 (en) * 2007-04-16 2020-11-25 Occlutech Holding AG Occluder for closing a cardiac auricle and manufacturing method therefor
US9034007B2 (en) 2007-09-21 2015-05-19 Insera Therapeutics, Inc. Distal embolic protection devices with a variable thickness microguidewire and methods for their use
WO2009086179A1 (en) * 2007-12-20 2009-07-09 Boston Scientific Scimed, Inc. Polymeric slotted tube coils
US8226312B2 (en) 2008-03-28 2012-07-24 Sanford, L.P. Valve door having a force directing component and retractable instruments comprising same
EP3970633A1 (en) 2008-04-21 2022-03-23 Covidien LP Braid-ball embolic devices and delivery systems
US10028747B2 (en) 2008-05-01 2018-07-24 Aneuclose Llc Coils with a series of proximally-and-distally-connected loops for occluding a cerebral aneurysm
US10716573B2 (en) 2008-05-01 2020-07-21 Aneuclose Janjua aneurysm net with a resilient neck-bridging portion for occluding a cerebral aneurysm
US8974487B2 (en) * 2008-05-01 2015-03-10 Aneuclose Llc Aneurysm occlusion device
US9675482B2 (en) 2008-05-13 2017-06-13 Covidien Lp Braid implant delivery systems
CN102137626A (en) 2008-07-22 2011-07-27 微治疗公司 Vascular remodeling device
US8221012B2 (en) 2008-11-07 2012-07-17 Sanford, L.P. Retractable instruments comprising a one-piece valve door actuating assembly
US20100131002A1 (en) * 2008-11-24 2010-05-27 Connor Robert A Stent with a net layer to embolize and aneurysm
US20100151227A1 (en) * 2008-12-17 2010-06-17 International Automative Components Group North America, Inc. Interior panel component for use with a vehicle and method for making
WO2010071856A1 (en) * 2008-12-19 2010-06-24 Tyco Healthcare Group, L.P. Method and apparatus for storage and/or introduction of implant for hollow anatomical structure
US8393814B2 (en) 2009-01-30 2013-03-12 Sanford, L.P. Retractable instrument having a two stage protraction/retraction sequence
WO2010096541A1 (en) * 2009-02-19 2010-08-26 Biomerix Corporation Vascular occlusion devices and methods
FR2943905B1 (en) * 2009-04-06 2011-04-22 Braun Medical Sas EMBOLIZATION IMPLANT
JP2012525336A (en) * 2009-04-27 2012-10-22 エラン ファーマシューティカルズ,インコーポレイテッド Alpha-4 integrin pyridinone antagonist
WO2010126877A1 (en) * 2009-04-30 2010-11-04 Medtronic, Inc. Shielding an implantable medical lead
US10639396B2 (en) 2015-06-11 2020-05-05 Microvention, Inc. Polymers
US9014787B2 (en) 2009-06-01 2015-04-21 Focal Therapeutics, Inc. Bioabsorbable target for diagnostic or therapeutic procedure
US8409269B2 (en) 2009-12-21 2013-04-02 Covidien Lp Procedures for vascular occlusion
US20110202016A1 (en) * 2009-08-24 2011-08-18 Arsenal Medical, Inc. Systems and methods relating to polymer foams
US9340555B2 (en) 2009-09-03 2016-05-17 Allergan, Inc. Compounds as tyrosine kinase modulators
US20110202085A1 (en) 2009-11-09 2011-08-18 Siddharth Loganathan Braid Ball Embolic Device Features
US9358140B1 (en) 2009-11-18 2016-06-07 Aneuclose Llc Stent with outer member to embolize an aneurysm
US8906057B2 (en) * 2010-01-04 2014-12-09 Aneuclose Llc Aneurysm embolization by rotational accumulation of mass
EP2528541B1 (en) 2010-01-28 2016-05-18 Covidien LP Vascular remodeling device
CN102740799A (en) 2010-01-28 2012-10-17 泰科保健集团有限合伙公司 Vascular remodeling device
US8425548B2 (en) 2010-07-01 2013-04-23 Aneaclose LLC Occluding member expansion and then stent expansion for aneurysm treatment
EP2613735B1 (en) 2010-09-10 2018-05-09 Covidien LP Devices for the treatment of vascular defects
US8998947B2 (en) * 2010-09-10 2015-04-07 Medina Medical, Inc. Devices and methods for the treatment of vascular defects
AU2012214240B2 (en) 2011-02-11 2015-03-12 Covidien Lp Two-stage deployment aneurysm embolization devices
US8607562B2 (en) * 2011-02-28 2013-12-17 GM Global Technology Operations LLC Shape memory alloy heat engines and energy harvesting systems
US9050435B2 (en) 2011-03-22 2015-06-09 Angiodynamics, Inc. High flow catheters
US20120245674A1 (en) 2011-03-25 2012-09-27 Tyco Healthcare Group Lp Vascular remodeling device
US9138232B2 (en) * 2011-05-24 2015-09-22 Aneuclose Llc Aneurysm occlusion by rotational dispensation of mass
US10137280B2 (en) * 2011-06-30 2018-11-27 Incube Labs, Llc System and method for treatment of hemorrhagic stroke
JP6100454B2 (en) * 2011-07-29 2017-03-22 アクセスポイント テクノロジーズ有限会社 Biological lumen occlusion device
WO2013039829A1 (en) * 2011-09-13 2013-03-21 Stryker Corporation Vaso-occlusive device
WO2013049448A1 (en) 2011-09-29 2013-04-04 Covidien Lp Vascular remodeling device
WO2014160320A2 (en) 2013-03-13 2014-10-02 Endoshape Inc. Continuous embolic coil and methods and devices for delivery of the same
US9011480B2 (en) 2012-01-20 2015-04-21 Covidien Lp Aneurysm treatment coils
WO2013119332A2 (en) 2012-02-09 2013-08-15 Stout Medical Group, L.P. Embolic device and methods of use
US9687245B2 (en) * 2012-03-23 2017-06-27 Covidien Lp Occlusive devices and methods of use
US20130289389A1 (en) 2012-04-26 2013-10-31 Focal Therapeutics Surgical implant for marking soft tissue
WO2014058589A1 (en) * 2012-10-08 2014-04-17 Cormatrix Cardiovascular, Inc. Multi-layer vascular prosthesis
RU2521833C2 (en) * 2012-10-18 2014-07-10 Заза Александрович Кавтеладзе Device for measuring pressure and introduction of medications into blood vessel aneurysm
US9301831B2 (en) 2012-10-30 2016-04-05 Covidien Lp Methods for attaining a predetermined porosity of a vascular device
US9452070B2 (en) 2012-10-31 2016-09-27 Covidien Lp Methods and systems for increasing a density of a region of a vascular device
US9314248B2 (en) 2012-11-06 2016-04-19 Covidien Lp Multi-pivot thrombectomy device
US9943427B2 (en) 2012-11-06 2018-04-17 Covidien Lp Shaped occluding devices and methods of using the same
CN104918565B (en) * 2012-11-13 2018-04-27 柯惠有限合伙公司 plugging device
US9295571B2 (en) 2013-01-17 2016-03-29 Covidien Lp Methods and apparatus for luminal stenting
US9157174B2 (en) 2013-02-05 2015-10-13 Covidien Lp Vascular device for aneurysm treatment and providing blood flow into a perforator vessel
US10835367B2 (en) 2013-03-08 2020-11-17 Limflow Gmbh Devices for fluid flow through body passages
AU2014226234B2 (en) 2013-03-08 2017-12-07 Limflow Gmbh Methods and systems for providing or maintaining fluid flow through body passages
US9463105B2 (en) 2013-03-14 2016-10-11 Covidien Lp Methods and apparatus for luminal stenting
CN105142545B (en) 2013-03-15 2018-04-06 柯惠有限合伙公司 Locking device
WO2014150288A2 (en) 2013-03-15 2014-09-25 Insera Therapeutics, Inc. Vascular treatment devices and methods
US10675039B2 (en) 2013-03-15 2020-06-09 Embo Medical Limited Embolisation systems
US8715314B1 (en) 2013-03-15 2014-05-06 Insera Therapeutics, Inc. Vascular treatment measurement methods
EP3756591A1 (en) 2013-03-15 2020-12-30 Embo Medical Limited Embolisation systems
US8715315B1 (en) 2013-03-15 2014-05-06 Insera Therapeutics, Inc. Vascular treatment systems
US10660645B2 (en) 2013-03-15 2020-05-26 Embo Medical Limited Embolization systems
US8679150B1 (en) 2013-03-15 2014-03-25 Insera Therapeutics, Inc. Shape-set textile structure based mechanical thrombectomy methods
US20140330299A1 (en) * 2013-05-06 2014-11-06 Sequent Medical, Inc. Embolic occlusion device and method
JP6002319B2 (en) * 2013-05-15 2016-10-05 グンゼ株式会社 Medical materials
US9968432B2 (en) 2013-06-28 2018-05-15 Cook Medical Technologies Llc Occlusion device including bundle of occlusion wires having preformed shapes
US9282970B2 (en) * 2013-09-30 2016-03-15 Covidien Lp Systems and methods for positioning and compacting a bodily implant
US9713475B2 (en) 2014-04-18 2017-07-25 Covidien Lp Embolic medical devices
CN106456183B (en) 2014-04-30 2019-09-20 Cerus血管内设备有限公司 Locking device
US9060777B1 (en) 2014-05-28 2015-06-23 Tw Medical Technologies, Llc Vaso-occlusive devices and methods of use
CN106604696A (en) 2014-05-28 2017-04-26 斯瑞克欧洲控股有限责任公司 Vaso-occlusive devices and methods of use
ES2933054T3 (en) 2014-07-25 2023-01-31 Hologic Inc Implantable devices and techniques for oncoplastic surgery
US9375333B1 (en) 2015-03-06 2016-06-28 Covidien Lp Implantable device detachment systems and associated devices and methods
US10159490B2 (en) 2015-05-08 2018-12-25 Stryker European Holdings I, Llc Vaso-occlusive devices
EP3344161B1 (en) * 2015-09-04 2023-12-20 The Texas A&M University System Shape memory polymer vessel occlusion device
US10478194B2 (en) 2015-09-23 2019-11-19 Covidien Lp Occlusive devices
US10314593B2 (en) 2015-09-23 2019-06-11 Covidien Lp Occlusive devices
CN108601862B (en) * 2015-12-02 2022-02-11 库克生物技术股份有限公司 Filamentous graft implants and methods of making and using same
CA3005686A1 (en) * 2015-12-07 2017-06-15 Cerus Endovascular Limited Occlusion device
EP3416568A4 (en) 2016-02-16 2019-10-16 Insera Therapeutics, Inc. Aspiration devices and anchored flow diverting devices
CA3016679A1 (en) 2016-03-11 2017-09-14 Cerus Endovascular Limited Occlusion device
US10478195B2 (en) 2016-08-04 2019-11-19 Covidien Lp Devices, systems, and methods for the treatment of vascular defects
EP4299086A2 (en) 2017-04-10 2024-01-03 LimFlow GmbH Devices for treating lower extremity vasculature
US10299799B1 (en) 2017-07-07 2019-05-28 John S. DeMeritt Micro-macro endovascular occlusion device and methodology
MX2020001999A (en) 2017-08-21 2020-07-20 Cerus Endovascular Ltd Occlusion device.
US10675036B2 (en) 2017-08-22 2020-06-09 Covidien Lp Devices, systems, and methods for the treatment of vascular defects
US11219502B2 (en) 2017-09-11 2022-01-11 Medtronic Advanced Energy, Llc Transformative shape-memory polymer tissue cavity marker devices, systems and deployment methods
US11589872B2 (en) * 2018-01-31 2023-02-28 Nanostructures, Inc. Vascular occlusion devices utilizing thin film nitinol foils
US11324567B2 (en) 2018-02-01 2022-05-10 Medtronic Advanced Energy, Llc Expandable tissue cavity marker devices, systems and deployment methods
EP3766435A4 (en) * 2018-03-22 2021-05-05 TERUMO Kabushiki Kaisha Embolus material
WO2020076833A1 (en) * 2018-10-09 2020-04-16 Limflow Gmbh Devices and methods for catheter alignment
US11129621B2 (en) 2018-12-17 2021-09-28 Covidien Lp Devices, systems, and methods for the treatment of vascular defects
CN113727671A (en) * 2019-01-31 2021-11-30 J·S·德梅里特 Micro-macro endovascular occlusion devices and methods
WO2020168181A1 (en) 2019-02-14 2020-08-20 Videra Surgical Inc. Fiducial marker for oncological and other procedures
EP3930773B1 (en) * 2019-03-01 2023-03-01 DSM IP Assets B.V. Medical implant component comprising a composite biotextile and method of making
CN113490516B (en) * 2019-03-01 2022-11-08 帝斯曼知识产权资产管理有限公司 Method for preparing composite biological textile and medical implant comprising composite biological textile
JP2023500067A (en) 2019-11-01 2023-01-04 リムフロウ・ゲゼルシャフト・ミット・ベシュレンクテル・ハフツング Devices and methods for increasing blood perfusion to distal limbs
CN114630627A (en) 2019-11-04 2022-06-14 柯惠有限合伙公司 Devices, systems, and methods for treating intracranial aneurysms
US11406404B2 (en) 2020-02-20 2022-08-09 Cerus Endovascular Limited Clot removal distal protection methods
CN114098879A (en) * 2020-08-31 2022-03-01 微创神通医疗科技(上海)有限公司 Hemangioma plugging device, hemangioma plugging treatment device and hemangioma plugging system
CN114246626A (en) * 2020-09-22 2022-03-29 微创神通医疗科技(上海)有限公司 Medical spring coil and conveying system comprising same
WO2023168081A2 (en) * 2022-03-03 2023-09-07 Polyembo, LLC Occlusive device with self-expanding struts

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5919224A (en) * 1997-02-12 1999-07-06 Schneider (Usa) Inc Medical device having a constricted region for occluding fluid flow in a body lumen
US6238403B1 (en) * 1999-10-04 2001-05-29 Microvention, Inc. Filamentous embolic device with expansible elements
US6475169B2 (en) * 1997-12-05 2002-11-05 Micrus Corporation Micro-strand cable with enhanced radiopacity

Family Cites Families (67)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US43816A (en) * 1864-08-09 Improvement in eyeleting-machines
US119177A (en) * 1871-09-19 Improvement in magnetic scissors
US169499A (en) * 1875-11-02 Improvement in rotary gang-plows
US199887A (en) * 1878-01-29 Improvement in fire-proof columns
US175408A (en) * 1876-03-28 Improvement in harness-pads
US14075A (en) * 1856-01-08 Improvement in cultivating-plows
US43585A (en) * 1864-07-19 Improvement in the manufacture of illuminating-gas from peat
US158282A (en) * 1874-12-29 Improvement in loom picker-rods
US1896071A (en) * 1931-04-24 1933-02-07 George A Clark Pessary
US2546754A (en) * 1947-11-19 1951-03-27 Jones John Leslie Vaginal applicator
US2616422A (en) * 1948-10-18 1952-11-04 Jones John Leslie Vaginal applicator
GB8428109D0 (en) * 1984-11-07 1984-12-12 Biocompatibles Ltd Biocompatible surfaces
US4890612A (en) * 1987-02-17 1990-01-02 Kensey Nash Corporation Device for sealing percutaneous puncture in a vessel
US5374261A (en) * 1990-07-24 1994-12-20 Yoon; Inbae Multifunctional devices for use in endoscopic surgical procedures and methods-therefor
US4985467A (en) * 1989-04-12 1991-01-15 Scotfoam Corporation Highly absorbent polyurethane foam
US5061274A (en) * 1989-12-04 1991-10-29 Kensey Nash Corporation Plug device for sealing openings and method of use
US5261916A (en) * 1991-12-12 1993-11-16 Target Therapeutics Detachable pusher-vasoocclusive coil assembly with interlocking ball and keyway coupling
US5312415A (en) * 1992-09-22 1994-05-17 Target Therapeutics, Inc. Assembly for placement of embolic coils using frictional placement
US5382259A (en) * 1992-10-26 1995-01-17 Target Therapeutics, Inc. Vasoocclusion coil with attached tubular woven or braided fibrous covering
US5690666A (en) * 1992-11-18 1997-11-25 Target Therapeutics, Inc. Ultrasoft embolism coils and process for using them
US5334210A (en) * 1993-04-09 1994-08-02 Cook Incorporated Vascular occlusion assembly
US5464650A (en) * 1993-04-26 1995-11-07 Medtronic, Inc. Intravascular stent and method
US5725546A (en) * 1994-06-24 1998-03-10 Target Therapeutics, Inc. Detachable microcoil delivery catheter
US5709934A (en) * 1994-11-22 1998-01-20 Tissue Engineering, Inc. Bipolymer foams having extracellular matrix particulates
US5891558A (en) * 1994-11-22 1999-04-06 Tissue Engineering, Inc. Biopolymer foams for use in tissue repair and reconstruction
US5690671A (en) * 1994-12-13 1997-11-25 Micro Interventional Systems, Inc. Embolic elements and methods and apparatus for their delivery
US5582619A (en) * 1995-06-30 1996-12-10 Target Therapeutics, Inc. Stretch resistant vaso-occlusive coils
ATE197388T1 (en) * 1995-06-30 2000-11-11 Target Therapeutics Inc EXPANSION-RESISTANT VASO-OCCLUSIVE SPIRAL
US5853418A (en) * 1995-06-30 1998-12-29 Target Therapeutics, Inc. Stretch resistant vaso-occlusive coils (II)
US5749894A (en) * 1996-01-18 1998-05-12 Target Therapeutics, Inc. Aneurysm closure method
US5713949A (en) * 1996-08-06 1998-02-03 Jayaraman; Swaminathan Microporous covered stents and method of coating
EP0900051A1 (en) * 1996-05-08 1999-03-10 Salviac Limited An occluder device
US5823198A (en) * 1996-07-31 1998-10-20 Micro Therapeutics, Inc. Method and apparatus for intravasculer embolization
US5891192A (en) * 1997-05-22 1999-04-06 The Regents Of The University Of California Ion-implanted protein-coated intralumenal implants
US6042592A (en) * 1997-08-04 2000-03-28 Meadox Medicals, Inc. Thin soft tissue support mesh
US6322576B1 (en) * 1997-08-29 2001-11-27 Target Therapeutics, Inc. Stable coil designs
ATE382309T1 (en) * 1997-11-07 2008-01-15 Salviac Ltd EMBOLIC PROTECTION DEVICE
AU739610B2 (en) * 1997-11-07 2001-10-18 Salviac Limited Implantable occluder devices for medical use
US6159165A (en) * 1997-12-05 2000-12-12 Micrus Corporation Three dimensional spherical micro-coils manufactured from radiopaque nickel-titanium microstrand
IE980241A1 (en) * 1998-04-02 1999-10-20 Salviac Ltd Delivery catheter with split sheath
US6015424A (en) * 1998-04-28 2000-01-18 Microvention, Inc. Apparatus and method for vascular embolization
US6113629A (en) * 1998-05-01 2000-09-05 Micrus Corporation Hydrogel for the therapeutic treatment of aneurysms
US6224630B1 (en) * 1998-05-29 2001-05-01 Advanced Bio Surfaces, Inc. Implantable tissue repair device
US6165193A (en) * 1998-07-06 2000-12-26 Microvention, Inc. Vascular embolization with an expansible implant
US6149664A (en) * 1998-08-27 2000-11-21 Micrus Corporation Shape memory pusher introducer for vasoocclusive devices
US6478773B1 (en) * 1998-12-21 2002-11-12 Micrus Corporation Apparatus for deployment of micro-coil using a catheter
US6375688B1 (en) * 1998-09-29 2002-04-23 Matsushita Electric Industrial Co., Ltd. Method of making solid electrolyte capacitor having high capacitance
US6102932A (en) * 1998-12-15 2000-08-15 Micrus Corporation Intravascular device push wire delivery system
US6383204B1 (en) * 1998-12-15 2002-05-07 Micrus Corporation Variable stiffness coil for vasoocclusive devices
US6221066B1 (en) * 1999-03-09 2001-04-24 Micrus Corporation Shape memory segmented detachable coil
US6245107B1 (en) * 1999-05-28 2001-06-12 Bret A. Ferree Methods and apparatus for treating disc herniation
US6280457B1 (en) * 1999-06-04 2001-08-28 Scimed Life Systems, Inc. Polymer covered vaso-occlusive devices and methods of producing such devices
US6617014B1 (en) * 1999-09-01 2003-09-09 Hydrophilix, Llc Foam composite
US6602261B2 (en) * 1999-10-04 2003-08-05 Microvention, Inc. Filamentous embolic device with expansile elements
CN1250167C (en) * 1999-10-04 2006-04-12 微温森公司 Filamentous embolic device with expansible elements
US6458127B1 (en) * 1999-11-22 2002-10-01 Csaba Truckai Polymer embolic elements with metallic coatings for occlusion of vascular malformations
US6638312B2 (en) * 2000-08-04 2003-10-28 Depuy Orthopaedics, Inc. Reinforced small intestinal submucosa (SIS)
US6723108B1 (en) * 2000-09-18 2004-04-20 Cordis Neurovascular, Inc Foam matrix embolization device
US6605101B1 (en) * 2000-09-26 2003-08-12 Microvention, Inc. Microcoil vaso-occlusive device with multi-axis secondary configuration
US7306598B2 (en) * 2000-11-24 2007-12-11 Dfine, Inc. Polymer matrix devices for treatment of vascular malformations
US6545097B2 (en) * 2000-12-12 2003-04-08 Scimed Life Systems, Inc. Drug delivery compositions and medical devices containing block copolymer
US6852330B2 (en) * 2000-12-21 2005-02-08 Depuy Mitek, Inc. Reinforced foam implants with enhanced integrity for soft tissue repair and regeneration
CA2365376C (en) * 2000-12-21 2006-03-28 Ethicon, Inc. Use of reinforced foam implants with enhanced integrity for soft tissue repair and regeneration
US7070584B2 (en) * 2001-02-20 2006-07-04 Kci Licensing, Inc. Biocompatible wound dressing
US6692510B2 (en) * 2001-06-14 2004-02-17 Cordis Neurovascular, Inc. Aneurysm embolization device and deployment system
US7608058B2 (en) * 2002-07-23 2009-10-27 Micrus Corporation Stretch resistant therapeutic device
AU2003303289A1 (en) * 2002-10-23 2004-09-28 Biomerix Corporation. Aneurysm treatment devices and methods

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5919224A (en) * 1997-02-12 1999-07-06 Schneider (Usa) Inc Medical device having a constricted region for occluding fluid flow in a body lumen
US6475169B2 (en) * 1997-12-05 2002-11-05 Micrus Corporation Micro-strand cable with enhanced radiopacity
US6238403B1 (en) * 1999-10-04 2001-05-29 Microvention, Inc. Filamentous embolic device with expansible elements

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008051279A1 (en) * 2006-03-24 2008-05-02 Biomerix Corp Self-expandable endovascular device for aneurysm occlusion
EP2904998A1 (en) * 2012-04-24 2015-08-12 Urogyn B.V. Occluding compound for a fallopian tube
US9839555B2 (en) 2012-04-24 2017-12-12 Urogyn B.V. Applicator for delivering an occluding compound in a fallopian tube
US11883246B2 (en) * 2012-11-21 2024-01-30 Trustees Of Boston University Tissue markers and uses thereof
US10736730B2 (en) 2015-01-20 2020-08-11 Neurogami Medical, Inc. Vascular implant
US10799225B2 (en) 2015-01-20 2020-10-13 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US10231722B2 (en) 2015-01-20 2019-03-19 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US10285678B2 (en) 2015-01-20 2019-05-14 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US10285679B2 (en) 2015-01-20 2019-05-14 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US10299775B2 (en) 2015-01-20 2019-05-28 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
WO2016118420A1 (en) * 2015-01-20 2016-07-28 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US10653403B2 (en) 2015-01-20 2020-05-19 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US9962146B2 (en) 2015-01-20 2018-05-08 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US9999413B2 (en) 2015-01-20 2018-06-19 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US10857012B2 (en) 2015-01-20 2020-12-08 Neurogami Medical, Inc. Vascular implant
US10925611B2 (en) 2015-01-20 2021-02-23 Neurogami Medical, Inc. Packaging for surgical implant
US11006940B2 (en) 2015-01-20 2021-05-18 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US11096679B2 (en) 2015-01-20 2021-08-24 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US11241223B2 (en) 2015-01-20 2022-02-08 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US11484319B2 (en) 2015-01-20 2022-11-01 Neurogami Medical, Inc. Delivery system for micrograft for treating intracranial aneurysms
US11627950B2 (en) 2015-01-20 2023-04-18 Neurogami Medical, Inc. Micrograft for the treatment of intracranial aneurysms and method for use
US11779452B2 (en) 2015-01-20 2023-10-10 Neurogami Medical, Inc. Vascular implant
US11786255B2 (en) 2015-01-20 2023-10-17 Neurogami Medical, Inc Packaging for surgical implant
US10420563B2 (en) 2016-07-08 2019-09-24 Neurogami Medical, Inc. Delivery system insertable through body lumen

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